Practice Test 49 - Algebra 1

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

  1. A car's value after tt years is modeled by V(t)=25000(0.90)tV(t)=25000(0.90)^t. Is this exponential growth, decay, or neither?
  2. Solve and check for extraneous solutions: xx−2=3\frac{x}{x-2}=3
  3. A population starts at 500 and decreases by 10% each year. Let tt be the number of years. Write the function P(t)P(t) that models the population.
  4. Function ff is given by the equation f(x)=−(x−1)2+6f(x)=-(x-1)^2+6. Function gg is described as: "A parabola that opens downward with vertex at (3,4)(3,4)." Which function has the larger maximum value?
  5. A bacteria culture is modeled by N(t)=500⋅btN(t)=500\cdot b^t. If it grows by 8% each hour, what is the value of the growth factor bb?
  6. Multiply: (2x−1)(x+5)(2x - 1)(x + 5)
  7. Let p(x)=3x−1p(x) = 3x - 1 and q(x)=x+13q(x) = \frac{x + 1}{3}. A student evaluates (p∘q)(5)(p \circ q)(5) by first computing p(5)=14p(5) = 14, then computing q(14)=5q(14) = 5, and concludes that (p∘q)(5)=5(p \circ q)(5) = 5. What error did the student make?
  8. Suppose we want the rule (ba)c=bac(b^a)^c=b^{ac} to remain true when a=12a=\tfrac{1}{2}. What property requires b1/2b^{1/2} to mean b\sqrt{b} (for b>0b>0)?
  9. Factor P(x)=x2+3x−10P(x)=x^2+3x-10 and use the zeros to determine the x-intercepts of the graph of y=P(x)y=P(x).
  10. Function hh is described verbally as: "A linear function with y-intercept 6 and slope −2." Function kk is given by k(x)=x+1k(x)=x+1. Which function has the greater rate of change (slope)?
  11. A nutritionist plans a meal with chicken and rice. Each serving of chicken provides 25g protein and 200 calories. Each serving of rice provides 5g protein and 150 calories. The meal must have at least 40g protein but no more than 650 calories. If cc represents servings of chicken and rr represents servings of rice, which system represents these nutritional constraints?
  12. A movie theater charges $9 per ticket plus a one-time online fee of $2. The total cost is T(x)=9x+2T(x) = 9x + 2. What is T(3)T(3)?
  13. What is the coefficient of y3y^3 in −2y3+y−1-2y^3+y-1?
  14. Convert 65 mi/hr65\ \text{mi/hr} to feet per second (ft/sec). Use 1 mi=5280 ft1\ \text{mi}=5280\ \text{ft} and 1 hr=3600 sec1\ \text{hr}=3600\ \text{sec}.
  15. A ball's height (in meters) after tt seconds is modeled by h(t)=−t2+4th(t) = -t^2 + 4t. At what times is the height zero (when the ball is on the ground)?
  16. A material's stretch factor is modeled by multiplying a constant calibration factor and an exponential response. Let f(x)=3f(x)=3 and g(x)=2xg(x)=2^x. Find (f⋅g)(x)(f\cdot g)(x).
  17. The equation x2−6x+k=0x^2 - 6x + k = 0 has exactly one real solution. If this equation is solved by completing the square, what is the value of the perfect square trinomial that results?
  18. A bakery uses the function C(n)=2.50n+15C(n)=2.50n+15 to model the cost (in dollars) to make nn cupcakes, where nn is the number of cupcakes. The bakery can make at most 120 cupcakes in one batch. What domain makes sense for nn?
  19. What is the maximum value of the function h(t)=−t2+4t+1h(t) = -t^2 + 4t + 1?​
  20. A student claims: "If aa and bb are rational numbers, then a+ba+b must be an integer." Which option correctly refutes the claim using correct reasoning about rational numbers?​​​

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