Solving Nonlinear Functions - PSAT Math

  1. Solve for xx: (x−4)(x+1)=0(x-4)(x+1)=0.
    x=4x=4 or x=−1x=-1. Set each factor to zero: x−4=0x-4=0 or x+1=0x+1=0.
  2. What does Δ=0\Delta=0 imply about the real solutions of ax2+bx+c=0ax^2+bx+c=0?
    11 real solution (a repeated root). Zero discriminant makes ±0=0\pm\sqrt{0}=0, giving one solution.
  3. What is the standard method to solve a(bx+c)2=da(bx+c)^2=d when a≠0a\ne 0 and d/a≥0d/a\ge 0?
    (bx+c)=±da(bx+c)=\pm\sqrt{\frac{d}{a}}. Isolate the squared term, then take square root of both sides.
  4. Identify the solutions of x4−16=0x^4-16=0.
    x=±2x=\pm 2. Factor as (x2−4)(x2+4)=0(x^2-4)(x^2+4)=0; only x2=4x^2=4 has real solutions.
  5. Identify the first step to solve f(x)=g(x)f(x)=g(x) when ff and gg are nonlinear functions.
    Set f(x)−g(x)=0f(x)-g(x)=0 and solve the resulting equation. Rearranging creates a single equation to solve.
  6. State the quadratic formula for solutions of ax2+bx+c=0ax^2+bx+c=0.
    x=−b±b2−4ac2ax=\frac{-b\pm\sqrt{b^2-4ac}}{2a}. Derived by completing the square on the standard form.
  7. What is the axis of symmetry for y=a(x−h)2+ky=a(x-h)^2+k?
    x=hx=h. The vertical line through the vertex where the parabola is symmetric.
  8. What is the solution set of x−1=3\sqrt{x-1}=3?
    x=10x=10. Square both sides: x−1=9x-1=9, so x=10x=10.
  9. Solve for xx: (x+1)2=16(x+1)^2=16.
    x=3x=3 or x=−5x=-5. Take square root: x+1=±4x+1=\pm 4, so x=3x=3 or x=−5x=-5.
  10. State the vertex xx-coordinate formula for y=ax2+bx+cy=ax^2+bx+c.
    x=−b2ax=-\frac{b}{2a}. The parabola's vertex occurs where the derivative equals zero.
  11. What are the solutions to x2+6x+9=0x^2+6x+9=0?
    x=−3x=-3. Perfect square (x+3)2=0(x+3)^2=0 has one repeated root.
  12. What is the zero-product property used after factoring?
    If ab=0ab=0, then a=0a=0 or b=0b=0. At least one factor must be zero for the product to be zero.
  13. What is the quadratic formula for solutions to ax2+bx+c=0ax^2+bx+c=0?
    x=−b±b2−4ac2ax=\frac{-b\pm\sqrt{b^2-4ac}}{2a}. Derived from completing the square on the general quadratic equation.
  14. What is the zero-product property used when solving factored equations?
    If ab=0ab=0, then a=0a=0 or b=0b=0. At least one factor must be zero for the product to be zero.
  15. What are the solutions to x2−9=0x^2-9=0?
    x=±3x=\pm 3. Factor as (x−3)(x+3)=0(x-3)(x+3)=0, then apply zero-product property.
  16. Solve for xx: x4−5x2+4=0x^4-5x^2+4=0.
    x=±1x=\pm 1 or x=±2x=\pm 2. Let u=x2u=x^2: u2−5u+4=0u^2-5u+4=0 factors to (u−1)(u−4)=0(u-1)(u-4)=0.
  17. What substitution turns a quadratic in x2x^2 into a linear equation in uu?
    Let u=x2u=x^2. This transforms equations like x4+3x2−4=0x^4+3x^2-4=0 into u2+3u−4=0u^2+3u-4=0.
  18. What are the solutions to 2x2−8=02x^2-8=0?
    x=±2x=\pm 2. Divide by 2: x2=4x^2=4, then take square roots.
  19. What are the solutions to x2+5x=0x^2+5x=0?
    x=0x=0 or x=−5x=-5. Factor out xx: x(x+5)=0x(x+5)=0, then apply zero-product property.
  20. What does b2−4ac=0b^2-4ac=0 tell you about the real solutions of ax2+bx+c=0ax^2+bx+c=0?
    One real solution (a double root). Zero discriminant makes ±0=0\pm\sqrt{0}=0, so both roots coincide.
  21. What is the solution set of x+1=3\sqrt{x+1}=3?
    x=8x=8. Square both sides: x+1=9x+1=9, so x=8x=8.
  22. What is the square root property for (x−h)2=k(x-h)^2=k?
    x=h±kx=h\pm\sqrt{k}. Take square root of both sides, giving two solutions.
  23. What does Δ>0\Delta>0 indicate about the real solutions of ax2+bx+c=0ax^2+bx+c=0?
    Two distinct real solutions. Positive discriminant means the square root yields two different values.
  24. What is the solution set of x2=−16x^2=-16 over the real numbers?
    No real solution. Square of real number cannot be negative.
  25. Solve for xx: x−1=5\sqrt{x-1}=5.
    x=26x=26. Square both sides: x−1=25x-1=25, so x=26x=26.
  26. What does Δ=b2−4ac=0\Delta=b^2-4ac=0 imply about the solutions of ax2+bx+c=0ax^2+bx+c=0?
    11 real double solution. Zero discriminant means both roots coincide.
  27. What are the real solutions to (x−2)2=9(x-2)^2=9?
    x=5x=5 or x=−1x=-1. Take square root: x−2=±3x-2=\pm 3, so x=5x=5 or x=−1x=-1.
  28. What are the solutions to x2−5x=0x^2-5x=0?
    x=0x=0 or x=5x=5. Factor as x(x−5)=0x(x-5)=0, giving two solutions.
  29. What is the solution set of x−1=3\sqrt{x-1}=3?
    x=10x=10. Square both sides: x−1=9x-1=9, so x=10x=10.
  30. What is the axis of symmetry of y=a(x−h)2+ky=a(x-h)^2+k?
    x=hx=h. In vertex form, the parabola is symmetric about the vertical line x=hx=h.
  31. What does Δ<0\Delta<0 imply about the real solutions of ax2+bx+c=0ax^2+bx+c=0?
    No real solutions. Negative discriminant means no real square root exists.
  32. What is the zero-product property used when factoring nonlinear equations?
    If ab=0ab=0, then a=0a=0 or b=0b=0. Allows solving factored equations by setting each factor to zero.
  33. What step is required after squaring both sides of an equation with radicals?
    Check for extraneous solutions. Squaring can introduce false solutions that don't satisfy the original.
  34. Identify the key step to solve x2=kx^2=k for real xx when k≥0k\ge 0.
    x=±kx=\pm\sqrt{k}. Take square root of both sides, considering both positive and negative roots.
  35. What are the solutions of x2−5x+6=0x^2-5x+6=0?
    x=2x=2 and x=3x=3. Factors to (x−2)(x−3)=0(x-2)(x-3)=0; apply zero-product property.
  36. What is the discriminant of ax2+bx+c=0ax^2+bx+c=0?
    b2−4acb^2-4ac. The expression under the square root in the quadratic formula.
  37. What are the solutions to x2=14x^2=\frac{1}{4}?
    x=±12x=\pm\frac{1}{2}. Take square root of both sides: x=±14x=\pm\sqrt{\frac{1}{4}}.
  38. What is the solution set of ∣x−3∣=5|x-3|=5?
    x=8x=8 and x=−2x=-2. Split into two cases: x−3=5x-3=5 or x−3=−5x-3=-5.
  39. What is the solution of x2=50x^2=50 in simplest radical form?
    x=±52x=\pm 5\sqrt{2}. Take square root of both sides: x=±50=±25⋅2=±52x=\pm\sqrt{50}=\pm\sqrt{25\cdot 2}=\pm 5\sqrt{2}.
  40. What is the standard form of a quadratic function?
    y=ax2+bx+cy=ax^2+bx+c. General polynomial form with degree 2; coefficients determine shape.
  41. Identify the vertex of y=(x−2)2+5y=(x-2)^2+5.
    (2,5)(2,5). In vertex form (x−h)2+k(x-h)^2+k, the vertex is at (h,k)(h,k).
  42. State the quadratic formula for solutions of ax2+bx+c=0ax^2+bx+c=0.
    x=−b±b2−4ac2ax=\frac{-b\pm\sqrt{b^2-4ac}}{2a}. Derived by completing the square on the standard form.
  43. What is the key restriction when solving a rational equation with denominators in xx?
    Exclude values that make any denominator equal to 00. Division by zero is undefined, so these values must be excluded.
  44. What is the discriminant for ax2+bx+c=0ax^2+bx+c=0, and what does its sign determine?
    Δ=b2−4ac\Delta=b^2-4ac; sign gives number of real solutions. Positive means 2 real roots, zero means 1, negative means none.
  45. What is the square root property for solving (x−h)2=k(x-h)^2=k?
    x=h±kx=h\pm\sqrt{k}. Take square root of both sides, remembering ±\pm for both solutions.
  46. What are the solutions of (x−4)(x+1)=0(x-4)(x+1)=0?
    x=4x=4 and x=−1x=-1. Apply zero-product property: each factor equals zero.
  47. What is the standard form of a circle centered at (h,k)(h,k) with radius rr?
    (x−h)2+(y−k)2=r2(x-h)^2+(y-k)^2=r^2. Distance formula squared: all points exactly rr units from (h,k)(h,k).
  48. What is the solution set of x2+5x=0x^2+5x=0?
    x=0x=0 and x=−5x=-5. Factor out xx: x(x+5)=0x(x+5)=0, so x=0x=0 or x=−5x=-5.
  49. What is the inverse operation used to solve x2=kx^2=k for real xx?
    x=±kx=\pm\sqrt{k} (requires k≥0k\ge 0). Take square root of both sides; negative kk has no real solutions.
  50. What is the substitution that turns a biquadratic x4+bx2+c=0x^4+bx^2+c=0 into a quadratic?
    Let u=x2u=x^2. Reduces the degree from 4 to 2, making it solvable by quadratic formula.
  51. What domain restriction must be stated for 1x−3\frac{1}{x-3} before solving equations?
    x≠3x\ne 3. The denominator cannot be zero, so exclude x=3x=3.
  52. Identify the method: What is the first step to solve (x−3)(x+5)=0(x-3)(x+5)=0?
    Set each factor equal to 00. Zero product property: if AB=0AB=0, then A=0A=0 or B=0B=0.
  53. What is the quadratic formula for solving ax2+bx+c=0ax^2+bx+c=0 in terms of aa, bb, and cc?
    x=−b±b2−4ac2ax=\frac{-b\pm\sqrt{b^2-4ac}}{2a}. Derived using completing the square on the general quadratic equation.
  54. Identify the solutions of x−1=3\sqrt{x-1}=3.
    x=10x=10. Square both sides: x−1=9x-1=9, so x=10x=10.
  55. What is the axis of symmetry for y=ax2+bx+cy=ax^2+bx+c?
    x=−b2ax=-\frac{b}{2a}. The xx-coordinate of the vertex, halfway between roots.
  56. What does Δ<0\Delta<0 indicate about the real solutions of ax2+bx+c=0ax^2+bx+c=0?
    No real solutions. Negative discriminant means Δ\sqrt{\Delta} is imaginary.
  57. What is the standard form of a quadratic equation to solve for its zeros?
    ax2+bx+c=0ax^2+bx+c=0 with a≠0a\ne 0. Standard form requires the equation to equal zero with a≠0a \ne 0.
  58. What is the first step to solve an equation with a rational expression in xx?
    Multiply both sides by the LCD. Clears denominators to create a polynomial equation.
  59. What is the solution set of 1x=2\frac{1}{x}=2?
    x=12x=\frac{1}{2}. Multiply both sides by xx: 1=2x1=2x, so x=12x=\frac{1}{2}.
  60. What does b2−4ac<0b^2-4ac<0 tell you about the real solutions of ax2+bx+c=0ax^2+bx+c=0?
    No real solutions. Negative discriminant gives imaginary square roots, no real values.
  61. What does Δ<0\Delta<0 tell you about the real solutions of ax2+bx+c=0ax^2+bx+c=0?
    No real solutions. Negative discriminant means square root of negative number, which isn't real.
  62. What is the vertex xx-coordinate of y=ax2+bx+cy=ax^2+bx+c in terms of aa and bb?
    x=−b2ax=-\frac{b}{2a}. The vertex lies on the axis of symmetry.
  63. Solve for xx: x2−5x+6=0x^2-5x+6=0.
    x=2x=2 or x=3x=3. Factors to (x−2)(x−3)=0(x-2)(x-3)=0 using zero-product property.
  64. Identify the substitution that makes x4−5x2+4=0x^4-5x^2+4=0 quadratic in one variable.
    Let u=x2u=x^2. Transforms to u2−5u+4=0u^2-5u+4=0, a standard quadratic form.
  65. What is the solution to the system y=x2y=x^2 and y=9y=9?
    (x,y)=(3,9)(x,y)=(3,9) and (x,y)=(−3,9)(x,y)=(-3,9). Substitute y=9y=9 into y=x2y=x^2: x2=9x^2=9, so x=±3x=\pm 3.
  66. Solve for xx: x2−9=0x^2-9=0.
    x=±3x=\pm 3. Factor as (x−3)(x+3)=0(x-3)(x+3)=0, giving x=3x=3 or x=−3x=-3.
  67. State the factored form of a quadratic with zeros r1r_1 and r2r_2.
    y=a(x−r1)(x−r2)y=a(x-r_1)(x-r_2). Each factor (x−r)(x-r) equals zero when xx equals that root.
  68. What does Δ=b2−4ac>0\Delta=b^2-4ac>0 imply about the solutions of ax2+bx+c=0ax^2+bx+c=0?
    22 distinct real solutions. Positive discriminant means the square root is real.
  69. Solve x2=49x^2=49 for xx.
    x=±7x=\pm 7. Take square root of both sides: x=±49x=\pm\sqrt{49}.
  70. What is the quadratic formula for solving ax2+bx+c=0ax^2+bx+c=0?
    x=−b±b2−4ac2ax=\frac{-b\pm\sqrt{b^2-4ac}}{2a}. Derived using completing the square on the general quadratic equation.
  71. What are the solutions of (x−2)(x+5)=0(x-2)(x+5)=0?
    x=2x=2 or x=−5x=-5. Apply zero-product property: each factor equals zero.
  72. What is the quadratic formula for solving ax2+bx+c=0ax^2+bx+c=0?
    x=−b±b2−4ac2ax=\frac{-b\pm\sqrt{b^2-4ac}}{2a}. Derived from completing the square on the standard form.
  73. What are the solutions to x2=49x^2=49?
    x=±7x=\pm 7. 49=7\sqrt{49}=7, so x=±7x=\pm 7.
  74. Solve for xx: x2=49x^2=49.
    x=±7x=\pm 7. Take square roots of both sides: x=±49=±7x=\pm\sqrt{49}=\pm 7.
  75. What is the vertex form of a quadratic function?
    y=a(x−h)2+ky=a(x-h)^2+k. Shows parabola with vertex at (h,k)(h,k) and vertical stretch factor aa.
  76. Solve x2−5x=0x^2-5x=0 for xx.
    x=0x=0 or x=5x=5. Factor out xx: x(x−5)=0x(x-5)=0, then use zero-product property.
  77. What are the solutions to (x−4)(x+1)=0(x-4)(x+1)=0?
    x=4x=4 or x=−1x=-1. Apply zero-product property to each factor.
  78. What is the solution set of 2x−1=1\frac{2}{x-1}=1?
    x=3x=3. Cross-multiply: 2=x−12=x-1, so x=3x=3.
  79. What are the solutions to (x−4)2=25(x-4)^2=25?
    x=9x=9 or x=−1x=-1. Take square root: x−4=±5x-4=\pm 5, so x=4±5x=4\pm 5.
  80. Solve for xx: x2+4x+5=0x^2+4x+5=0.
    No real solutions. Discriminant is 16−20=−4<016-20=-4<0, so no real solutions exist.
  81. What is the solution set of x+2=x\sqrt{x+2}=x?
    x=2x=2. Square both sides: x+2=x2x+2=x^2; solve x2−x−2=0x^2-x-2=0 to get x=2x=2 (reject x=−1x=-1).
  82. What are the solutions to (x−4)(x+1)=0(x-4)(x+1)=0?
    x=4x=4 or x=−1x=-1. Apply zero-product property: each factor can equal zero.
  83. What is the axis of symmetry of y=ax2+bx+cy=ax^2+bx+c written in terms of aa and bb?
    x=−b2ax=-\frac{b}{2a}. The parabola's line of symmetry passes through the vertex.
  84. Solve for xx: x2−5x=0x^2-5x=0.
    x=0x=0 or x=5x=5. Factor out xx: x(x−5)=0x(x-5)=0, so x=0x=0 or x=5x=5.
  85. What are the solutions to x2=16x^2=16?
    x=±4x=\pm 4. Take square root of both sides: x=±16x=\pm\sqrt{16}.
  86. What is the solution of x−1=4\sqrt{x-1}=4?
    x=17x=17. Square both sides: x−1=16x-1=16, so x=17x=17.
  87. Solve for xx: 3x2−12=03x^2-12=0.
    x=±2x=\pm 2. Add 12 to both sides: 3x2=123x^2=12, so x2=4x^2=4, thus x=±2x=\pm 2.
  88. Solve for xx: x12=3x^{\frac{1}{2}}=3.
    x=9x=9. Square both sides: (x12)2=32(x^{\frac{1}{2}})^2=3^2.
  89. What does Δ<0\Delta<0 imply about the solutions of ax2+bx+c=0ax^2+bx+c=0?
    No real solutions (two complex solutions). Negative discriminant requires imaginary numbers for the square root.
  90. What is the solution to x2−6x+9=0x^2-6x+9=0?
    x=3x=3. Perfect square: (x−3)2=0(x-3)^2=0, so x=3x=3 (double root).
  91. What does b2−4ac>0b^2-4ac>0 tell you about the real solutions of ax2+bx+c=0ax^2+bx+c=0?
    Two distinct real solutions. Positive discriminant means the square root is real, yielding two values.
  92. Solve for xx: x+1=3\sqrt{x+1}=3.
    x=8x=8. Square both sides: x+1=9x+1=9, so x=8x=8.
  93. What does it mean if Δ<0\Delta<0 for ax2+bx+c=0ax^2+bx+c=0?
    No real solutions. Negative discriminant means the parabola doesn't cross the x-axis.
  94. What does b2−4ac=0b^2-4ac=0 tell you about solutions of ax2+bx+c=0ax^2+bx+c=0?
    11 real solution (a double root). Zero discriminant means ±0=0\pm\sqrt{0}=0, giving one repeated root.
  95. Solve 1x−2=3\frac{1}{x-2}=3 for xx.
    x=73x=\frac{7}{3}. Cross-multiply: 1=3(x−2)1=3(x-2), so 1=3x−61=3x-6.
  96. Identify the xx-intercepts of y=a(x−r1)(x−r2)y=a(x-r_1)(x-r_2).
    x=r1x=r_1 and x=r2x=r_2. The parabola crosses the xx-axis where each factor equals zero.
  97. What does Δ=0\Delta=0 indicate about the real solutions of ax2+bx+c=0ax^2+bx+c=0?
    One real solution (a double root). Zero discriminant makes ±0=0\pm\sqrt{0}=0, giving one repeated root.
  98. What does b2−4ac<0b^2-4ac<0 tell you about solutions of ax2+bx+c=0ax^2+bx+c=0?
    No real solutions. Negative discriminant means square root of negative number is not real.
  99. What is the zero-product property used after factoring an equation like (x−3)(x+2)=0(x-3)(x+2)=0?
    If ab=0ab=0, then a=0a=0 or b=0b=0. A product equals zero only when at least one factor is zero.
  100. What is the standard form of a quadratic equation in xx?
    ax2+bx+c=0ax^2+bx+c=0 with a≠0a\ne 0. The general form with aa as the coefficient of x2x^2.
  101. Solve for xx: x2+6x+9=0x^2+6x+9=0.
    x=−3x=-3. This is (x+3)2=0(x+3)^2=0, a perfect square with one repeated root.
  102. Solve for xx: x4−16=0x^4-16=0.
    x=±2x=\pm 2. Factor as (x2−4)(x2+4)=0(x^2-4)(x^2+4)=0; only x2=4x^2=4 has real solutions.
  103. Solve for xx: x2+6x+9=0x^2+6x+9=0.
    x=−3x=-3. Perfect square: (x+3)2=0(x+3)^2=0 gives a double root.
  104. Solve x2−6x+9=0x^2-6x+9=0 for xx.
    x=3x=3. Perfect square: (x−3)2=0(x-3)^2=0, so x−3=0x-3=0.
  105. What is the solution set of x2+1=0x^2+1=0 over the real numbers?
    No real solutions. x2=−1x^2=-1 has no real square root.
  106. What is the standard form of a quadratic equation in xx?
    ax2+bx+c=0ax^2+bx+c=0 with a≠0a\ne 0. The coefficient aa must be nonzero for a quadratic equation.
  107. What is the definition of a solution to f(x)=g(x)f(x)=g(x)?
    Any xx where f(x)f(x) and g(x)g(x) are equal. The x-values where the two functions intersect.
  108. What is the axis of symmetry for y=a(x−h)2+ky=a(x-h)^2+k?
    x=hx=h. The parabola is symmetric about the vertical line through the vertex.
  109. What is the quadratic formula for solutions to ax2+bx+c=0ax^2+bx+c=0?
    x=−b±b2−4ac2ax=\frac{-b\pm\sqrt{b^2-4ac}}{2a}. Derived from completing the square on the general quadratic equation.
  110. Solve for xx: x2−9=0x^2-9=0.
    x=±3x=\pm 3. Factor as (x−3)(x+3)=0(x-3)(x+3)=0.
  111. Solve x2+2x−8=0x^2+2x-8=0 for xx.
    x=2x=2 or x=−4x=-4. Factor as (x+4)(x−2)=0(x+4)(x-2)=0 or use quadratic formula.
  112. Solve for xx: (x−3)2=16(x-3)^2=16.
    x=7x=7 or x=−1x=-1. x−3=±4x-3=\pm 4 gives x=7x=7 or x=−1x=-1.
  113. Identify the first step to solve x2=49x^2=49 over the real numbers.
    Take square roots: x=±49x=\pm\sqrt{49}. Square root gives both positive and negative values.
  114. What are the solutions to x4−5x2=0x^4-5x^2=0?
    x=0x=0 or x=±5x=\pm\sqrt{5}. Factor as x2(x2−5)=0x^2(x^2-5)=0, giving x=0x=0 or x2=5x^2=5.
  115. State the quadratic formula for solutions of ax2+bx+c=0ax^2+bx+c=0.
    x=−b±b2−4ac2ax=\frac{-b\pm\sqrt{b^2-4ac}}{2a}. Derived by completing the square on the general quadratic equation.
  116. What is the axis of symmetry formula for y=ax2+bx+cy=ax^2+bx+c?
    x=−b2ax=-\frac{b}{2a}. The parabola's line of symmetry passes through the vertex.
  117. What are the real solutions to x4−16=0x^4-16=0?
    x=±2x=\pm 2. Since x4=16x^4=16, take fourth root: x=±164=±2x=\pm\sqrt[4]{16}=\pm 2.
  118. What substitution can turn x4−5x2+4=0x^4-5x^2+4=0 into a quadratic equation?
    Let u=x2u=x^2. Transforms the quartic into u2−5u+4=0u^2-5u+4=0 for easier solving.
  119. Solve for xx: x+1x−2=3\frac{x+1}{x-2}=3 and state any restriction on xx.
    x=72x=\frac{7}{2}, with x≠2x\ne 2. Cross-multiply: x+1=3(x−2)x+1=3(x-2), then solve.
  120. What are the solutions to x=5\sqrt{x}=5?
    x=25x=25. Square both sides: x=25x=25 (check: 25=5\sqrt{25}=5 ✓).
  121. Solve for xx: x2=−16x^2= -16 over the real numbers.
    No real solution. Square roots of negative numbers aren't real.
  122. Identify the extraneous-solution risk when solving an equation by squaring both sides.
    Squaring can introduce extraneous solutions; check in the original equation. Squaring both sides can create false solutions not in the original.
  123. What is the discriminant of ax2+bx+c=0ax^2+bx+c=0, used to classify the number of real solutions?
    Δ=b2−4ac\Delta=b^2-4ac. Appears under the square root in the quadratic formula.
  124. What does b2−4ac>0b^2-4ac>0 tell you about solutions of ax2+bx+c=0ax^2+bx+c=0?
    22 distinct real solutions. Positive discriminant means the square root yields two different values.
  125. What is the axis of symmetry for f(x)=ax2+bx+cf(x)=ax^2+bx+c?
    x=−b2ax=-\frac{b}{2a}. The vertical line through the vertex, found from −b2a-\frac{b}{2a}.
  126. Solve for xx: x2+2x−3=0x^2+2x-3=0.
    x=1x=1 or x=−3x=-3. Factor as (x−1)(x+3)=0(x-1)(x+3)=0 or use the quadratic formula.
  127. Solve for xx: 2x2−8x=02x^2-8x=0.
    x=0x=0 or x=4x=4. Factor out 2x2x: 2x(x−4)=02x(x-4)=0, so x=0x=0 or x=4x=4.
  128. What does b2−4ac<0b^2-4ac<0 imply about the solutions of ax2+bx+c=0ax^2+bx+c=0?
    No real solutions (two complex solutions). Negative discriminant means parabola doesn't cross x-axis.
  129. What does Δ>0\Delta>0 imply about the real solutions of ax2+bx+c=0ax^2+bx+c=0?
    22 distinct real solutions. Positive discriminant means the square root yields two different values.
  130. Solve for xx: 2x2−8x=02x^2-8x=0.
    x=0x=0 or x=4x=4. Factor out 2x2x: 2x(x−4)=02x(x-4)=0, so x=0x=0 or x=4x=4.
  131. Solve for xx: x2−6x+9=0x^2-6x+9=0.
    x=3x=3. Perfect square: (x−3)2=0(x-3)^2=0.
  132. Find the real solutions of x2=49x^2=49.
    x=±7x=\pm 7. 49=7\sqrt{49}=7, so x=±7x=\pm 7.
  133. What does b2−4ac=0b^2-4ac=0 imply about the real solutions of ax2+bx+c=0ax^2+bx+c=0?
    One real solution (double root). Zero discriminant means parabola touches x-axis once.
  134. What is the discriminant of ax2+bx+c=0ax^2+bx+c=0?
    b2−4acb^2-4ac. This expression determines the nature and number of real solutions.
  135. What substitution is used to solve a quadratic in x2x^2, such as x4+5x2+4=0x^4+5x^2+4=0?
    Let u=x2u=x^2. Transforms to u2+5u+4=0u^2+5u+4=0, a standard quadratic.
  136. What are the solutions to x2−6x+9=0x^2-6x+9=0?
    x=3x=3. Perfect square (x−3)2=0(x-3)^2=0 has one repeated root.
  137. What does Δ>0\Delta>0 tell you about the real solutions of ax2+bx+c=0ax^2+bx+c=0?
    22 distinct real solutions. Positive discriminant means the square root yields two different values.
  138. What is the discriminant of ax2+bx+c=0ax^2+bx+c=0 used to classify solutions?
    Δ=b2−4ac\Delta=b^2-4ac. Determines the nature of roots; appears under the square root in the quadratic formula.
  139. What substitution can turn ax4+bx2+c=0ax^4+bx^2+c=0 into a quadratic?
    Let u=x2u=x^2. This reduces the quartic to au2+bu+c=0au^2+bu+c=0, a quadratic in uu.
  140. What is the solution to the system y=x2y=x^2 and y=x+2y=x+2?
    (x,y)=(2,4)(x,y)=(2,4) and (x,y)=(−1,1)(x,y)=(-1,1). Set x2=x+2x^2=x+2: x2−x−2=0x^2-x-2=0 factors as (x−2)(x+1)=0(x-2)(x+1)=0.
  141. Solve for xx: x2=2x+8x^2=2x+8.
    x=4x=4 or x=−2x=-2. Rearrange to x2−2x−8=0x^2-2x-8=0, factor as (x−4)(x+2)=0(x-4)(x+2)=0.
  142. What are the solutions of x2−9=0x^2-9=0?
    x=±3x=\pm 3. Factor as (x−3)(x+3)=0(x-3)(x+3)=0 and apply zero-product property.
  143. Identify the solutions of (x−5)(x+1)=0(x-5)(x+1)=0.
    x=5x=5 or x=−1x=-1. Set each factor to zero: x−5=0x-5=0 gives x=5x=5, x+1=0x+1=0 gives x=−1x=-1.
  144. What is the zero-product property used when factoring gives (A)(B)=0(A)(B)=0?
    A=0A=0 or B=0B=0. A product equals zero only when at least one factor equals zero.
  145. What are the solutions to x2+6x+9=0x^2+6x+9=0?
    x=−3x=-3. Perfect square (x+3)2=0(x+3)^2=0 has one repeated root.
  146. What is the zero-product property used after factoring an equation?
    If ab=0ab=0, then a=0a=0 or b=0b=0. At least one factor must equal zero for product to be zero.
  147. What does b2−4ac>0b^2-4ac>0 imply about the real solutions of ax2+bx+c=0ax^2+bx+c=0?
    Two distinct real solutions. Positive discriminant means parabola crosses x-axis twice.
  148. Identify the solutions of 1x−2=3\frac{1}{x-2}=3.
    x=73x=\frac{7}{3}. Cross-multiply: 1=3(x−2)1=3(x-2), so 1=3x−61=3x-6 and x=73x=\frac{7}{3}.
  149. What substitution turns ax4+bx2+c=0ax^4+bx^2+c=0 into a quadratic equation?
    Let u=x2u=x^2. Reduces quartic to quadratic form au2+bu+c=0au^2+bu+c=0.
  150. What is the solution set of x2−5x+6=0x^2-5x+6=0?
    x=2x=2 or x=3x=3. Factors to (x−2)(x−3)=0(x-2)(x-3)=0, then use zero-product property.
  151. Identify the xx-intercepts of a graph in terms of solving an equation.
    Solutions to f(x)=0f(x)=0. Where the graph crosses the x-axis, so y=0y=0.
  152. Solve for xx: x2−5x=0x^2-5x=0.
    x=0x=0 or x=5x=5. Factor out xx: x(x−5)=0x(x-5)=0.
  153. What is the correct first step to solve a rational equation like p(x)q(x)=r\frac{p(x)}{q(x)}=r?
    Multiply both sides by q(x)q(x), with q(x)≠0q(x)\ne 0. Clears the denominator to create a polynomial equation.
  154. What is the key restriction when squaring both sides to solve a radical equation?
    Check for extraneous solutions in the original equation. Squaring can introduce false solutions that don't satisfy the original.
  155. What are the solutions to x2+4x+3=0x^2+4x+3=0?
    x=−1x=-1 or x=−3x=-3. Factor as (x+1)(x+3)=0(x+1)(x+3)=0 or use quadratic formula.
  156. What is the discriminant for ax2+bx+c=0ax^2+bx+c=0, used to classify solutions?
    Δ=b2−4ac\Delta=b^2-4ac. Appears under the square root in the quadratic formula; determines solution types.
  157. Identify the substitution that turns ax4+bx2+c=0ax^4+bx^2+c=0 into a quadratic.
    Let u=x2u=x^2. Reduces the quartic to au2+bu+c=0au^2+bu+c=0, a quadratic in uu.
  158. What is the vertex xx-coordinate of y=a(x−h)2+ky=a(x-h)^2+k?
    hh. In vertex form, (h,k)(h,k) is the vertex point.
  159. Identify the required restriction when solving p(x)q(x)=r\frac{p(x)}{q(x)}=r.
    Exclude values where q(x)=0q(x)=0. Division by zero is undefined, so check denominator.
  160. Solve for xx: 2x2−8x=02x^2-8x=0.
    x=0x=0 or x=4x=4. Factor out 2x2x: 2x(x−4)=02x(x-4)=0, so x=0x=0 or x=4x=4.
  161. Solve for xx: 2x2−8=02x^2-8=0.
    x=±2x=\pm 2. x2=4x^2=4, so x=±2x=\pm 2.
  162. Solve for xx: (x−3)(x+5)=0(x-3)(x+5)=0.
    x=3x=3 or x=−5x=-5. Apply zero product property: x−3=0x-3=0 or x+5=0x+5=0.
  163. What is the solution of 1x=3\frac{1}{x}=3?
    x=13x=\frac{1}{3}. Multiply both sides by xx: 1=3x1=3x, so x=13x=\frac{1}{3}.
  164. Solve 2x=82^x=8 for xx.
    x=3x=3. Since 8=238=2^3, we have 2x=232^x=2^3, so x=3x=3.
  165. What are the solutions to x2−9=0x^2-9=0?
    x=±3x=\pm 3. Factor as (x−3)(x+3)=0(x-3)(x+3)=0, then apply zero-product property.
  166. Identify the extraneous-solution check after squaring both sides of an equation.
    Substitute solutions into the original equation. Squaring can introduce false solutions that don't satisfy the original.
  167. Identify the solutions of x2−9=0x^2-9=0.
    x=±3x=\pm 3. Factor as (x−3)(x+3)=0(x-3)(x+3)=0, then apply zero-product property.
  168. What is the domain restriction when solving g(x)=c\sqrt{g(x)}=c over the reals?
    g(x)≥0g(x)\ge 0. Square roots require non-negative values under the radical.
  169. What does it mean if Δ=0\Delta=0 for ax2+bx+c=0ax^2+bx+c=0?
    11 real solution (double root). Zero discriminant means the parabola touches the x-axis once.
  170. What is the solution of 2x2−8x=02x^2-8x=0?
    x=0x=0 and x=4x=4. Factor out 2x2x: 2x(x−4)=02x(x-4)=0, giving x=0x=0 or x=4x=4.
  171. What is the zero-product property used when solving factored equations?
    If ab=0ab=0, then a=0a=0 or b=0b=0. At least one factor must be zero for product to be zero.
  172. What is the vertex xx-coordinate of y=ax2+bx+cy=ax^2+bx+c?
    x=−b2ax=-\frac{b}{2a}. The axis of symmetry passes through the vertex.
  173. What are the solutions to 2x2−8x=02x^2-8x=0?
    x=0x=0 or x=4x=4. Factor out 2x2x: 2x(x−4)=02x(x-4)=0, so x=0x=0 or x=4x=4.
  174. What does it mean if Δ>0\Delta>0 for ax2+bx+c=0ax^2+bx+c=0?
    22 distinct real solutions. Positive discriminant means the parabola crosses the x-axis twice.
  175. What is the solution of x2−9=0x^2-9=0?
    x=±3x=\pm 3. Factor as (x−3)(x+3)=0(x-3)(x+3)=0, then apply zero-product property.
  176. What is the standard form of a quadratic function?
    f(x)=ax2+bx+cf(x)=ax^2+bx+c. The general form with coefficients aa, bb, and cc.
  177. What is the key first step to solve an equation containing  \sqrt{\,} terms?
    Isolate the radical term before squaring. Ensures only the radical is on one side before eliminating it.
  178. What is the vertex xx-coordinate formula for y=ax2+bx+cy=ax^2+bx+c?
    x=−b2ax=-\frac{b}{2a}. The axis of symmetry passes through the vertex of the parabola.
  179. What does Δ=0\Delta=0 tell you about the real solutions of ax2+bx+c=0ax^2+bx+c=0?
    11 real double root. Zero discriminant makes ±0=0\pm\sqrt{0}=0, giving one repeated solution.
  180. What is the zero-product property used to solve (x−p)(x−q)=0(x-p)(x-q)=0?
    x=px=p or x=qx=q. If a product equals zero, at least one factor must be zero.
  181. Identify the method to solve ax=ba^x=b for xx when a>0a>0, a≠1a\ne^1, b>0b>0.
    Take logs: x=log⁡(b)log⁡(a)x=\frac{\log(b)}{\log(a)}. Logarithms convert exponential equations to linear form.
  182. State the vertex form of a quadratic function.
    y=a(x−h)2+ky=a(x-h)^2+k. Shows the vertex at (h,k)(h,k) and vertical stretch factor aa.
  183. What is the equation of a parabola with vertex (h,k)(h,k) opening up or down?
    y=a(x−h)2+ky=a(x-h)^2+k. The vertex form shows transformations from y=x2y=x^2.
  184. Identify the solutions of x2+6x+9=0x^2+6x+9=0.
    x=−3x=-3. Perfect square (x+3)2=0(x+3)^2=0 has one repeated root.
  185. What are the solutions to x4−5x2+4=0x^4-5x^2+4=0 over the real numbers?
    x=±1x=\pm 1 or x=±2x=\pm 2. Let u=x2u=x^2: u2−5u+4=0u^2-5u+4=0 gives u=1,4u=1,4, so x=±1,±2x=\pm 1, \pm 2.
  186. What is the solution of 2x2−8x=02x^2-8x=0?
    x=0x=0 or x=4x=4. Factor out 2x2x: 2x(x−4)=02x(x-4)=0, so x=0x=0 or x=4x=4.
  187. Solve x+5=4\sqrt{x+5}=4 for xx.
    x=11x=11. Square both sides: x+5=16x+5=16, so x=11x=11.

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