Practice Test 37 - Algebra 2

20 questions. Answer them in any order, then submit to see your score and every explanation.

  1. A car rental company charges a daily rate plus a fixed service fee. The total cost is modeled by C=42d+18C = 42d + 18, where dd is the number of days rented. In this model, what does the parameter 1818 represent?
  2. Which identity allows you to factor the expression a2−b2a^2-b^2 as a product of two linear factors?
  3. Recognize a difference of cubes structure and factor: x3−27x^3 - 27
  4. Use zeros to construct a rough graph of the polynomial p(x)=(x+2)(x−1)2(x−4).p(x)=(x+2)(x-1)^2(x-4). Identify the zeros (with multiplicities), state whether the graph crosses or touches the x-axis at each zero, and determine the end behavior.
  5. If in=−1i^n = -1 where nn is a positive integer, which statement about nn must be true?
  6. Find xx in 4⋅2x/3=304\cdot 2^{x/3}=30. Express the solution as a logarithm (base 2) and approximate using technology.​​​
  7. Over the real numbers, a quadratic ax2+bx+c=0ax^2+bx+c=0 can have 0, 1, or 2 real solutions. Over the complex numbers, it always has exactly 2 solutions counting multiplicity. The discriminant b2−4acb^2-4ac determines the solution type: >0>0 two distinct real, =0=0 one repeated real (multiplicity 2), <0<0 two complex conjugates. For x2+6x+9=0x^2+6x+9=0, which statement is correct?
  8. Multiply and simplify using i2=−1i^2 = -1: (3+2i)(1−4i)(3 + 2i)(1 - 4i). Express your answer in standard form a+bia + bi.
  9. Write an expression for f−1(x)f^{-1}(x) given f(x)=3x−7f(x)=3x-7.
  10. Graph p(x)=x5−5x3+4xp(x)=x^5-5x^3+4x by finding its zeros (from factoring) and using end behavior to make a rough sketch.
  11. Let the parent function be f(x)=1xf(x)=\frac{1}{x}. Describe the transformations that change f(x)f(x) to g(x)=f(x)−2.g(x)=f(x)-2.
  12. Find the modulus rr and argument θ\theta (in degrees) of 3−3i3-3i, then write it in polar form r(cos⁡θ+isin⁡θ)r(\cos\theta+i\sin\theta). Use r=a2+b2r=\sqrt{a^2+b^2} and θ=arctan⁡(ba)\theta=\arctan\left(\frac{b}{a}\right) with quadrant adjustment.
  13. Complete the square to rewrite the expression in vertex form (a perfect square plus a constant): x2+8x+20x^2+8x+20
  14. Over the real numbers, x2+9x^2+9 does not factor. Over the complex numbers, use the difference of squares identity u2−v2=(u+v)(u−v)u^2-v^2=(u+v)(u-v) by writing x2+9=x2−(3i)2x^2+9=x^2-(3i)^2. Which is the correct factorization over C\mathbb{C}?
  15. Use log properties to expand: log⁡7((xy2)3z).\log_7\left(\frac{(xy^2)^3}{\sqrt{z}}\right). Write your answer as a sum/difference of logs with coefficients.
  16. For the quadratic equation x2+4x+4=0x^2+4x+4=0 (a case of ax2+bx+c=0ax^2+bx+c=0 with real coefficients), remember: every quadratic has exactly 2 complex solutions counting multiplicity. The discriminant b2−4acb^2-4ac determines whether the solutions are 2 distinct real, 1 repeated real (counted twice), or 2 complex conjugates. Which statement correctly describes the solutions (including multiplicity)?
  17. Marcus is solving the system {5x+2y=193x−4y=−13\begin{cases} 5x + 2y = 19 \\ 3x - 4y = -13 \end{cases} using elimination. He decides to eliminate yy by multiplying the first equation by 2. What should he multiply the second equation by to successfully eliminate yy?
  18. A data set shows the balance in an account at the end of each quarter: Quarter: 0, 1, 2, 3 Balance ($): 2,000; 2,160; 2,332.8; 2,519.424 From the table, what is the percent growth rate per quarter?
  19. Write the system with missing variables as a matrix equation AX=BAX=B (use variable order x,y,zx, y, z): {x+3y=52x−z=1y+2z=4 \begin{cases} x+3y=5\\ 2x-z=1\\ y+2z=4 \end{cases}
  20. A complex number zz satisfies ∣z∣=4|z| = 4. On the complex plane (real axis horizontal, imaginary axis vertical), what set of points represents all such zz?

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