Practice Test 43 - Algebra 1

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

  1. A movie theater charges $9 for a ticket plus $3 for each snack you buy. Let CC be the total cost (in dollars) and let ss be the number of snacks. What equation represents this relationship?
  2. The expression 3x2−21x+363x^2 - 21x + 36 represents the area of a rectangle where both dimensions are linear expressions in xx. After factoring completely, if the dimensions are (x−a)(x - a) and 3(x−b)3(x - b) where aa and bb are positive constants, what is the value of a⋅ba \cdot b?
  3. A phone battery percentage is modeled by B(t)=100(0.97)tB(t)=100(0.97)^t, where tt is measured in hours. What is the percent decay rate per hour?
  4. Which property justifies the step from x−14=3\frac{x-1}{4}=3 to x−1=12x-1=12?​
  5. A discounted price can be modeled by S=P(1−r)S = P(1 - r), where PP is the original price, rr is the discount rate (as a decimal), and SS is the sale price. Solve for rr in terms of PP and SS.
  6. Write both a recursive formula and an explicit formula for the arithmetic sequence 4,9,14,19,…4, 9, 14, 19, \dots.
  7. A bouncing ball rises to 80%80\% of its previous height after each bounce. The first bounce rises to 1010 ft. The total of the first 55 bounce heights is 10+10(0.8)+10(0.8)2+10(0.8)3+10(0.8)4.10 + 10(0.8) + 10(0.8)^2 + 10(0.8)^3 + 10(0.8)^4. Using Sn=a(1−rn)1−rS_n = \frac{a(1-r^n)}{1-r} with a=10a=10, r=0.8r=0.8, n=5n=5, what is the sum of these bounce heights?
  8. In geometry, the volume of a rectangular prism is V=lwhV = lwh, where VV is volume, ll is length, ww is width, and hh is height. Solve V=lwhV = lwh for hh.
  9. For h(x)=2x+1h(x) = 2x + 1, what is h(a+3)h(a + 3)?
  10. The revenue function for selling xx items is R(x)=x2−6x+5R(x)=x^2-6x+5. Break-even occurs when R(x)=0R(x)=0. What are the solutions to x2−6x+5=0x^2-6x+5=0?
  11. A ball's height (in meters) after tt seconds is modeled by a function H(t)H(t), and the model is only intended to be used for 0≤t≤60\le t\le 6. What is the domain of HH in this context? (Use interval notation.)
  12. Multiply: 3x(2x2−5x+1)3x(2x^2 - 5x + 1)
  13. Find the exponential function y=a⋅bxy=a\cdot b^x that passes through the points (0,5)(0, 5) and (2,45)(2, 45).
  14. Solve by factoring: x2+5x+6=0x^2 + 5x + 6 = 0
  15. A rental car company charges a flat fee plus a per-mile rate. Two customers provide the following data: Customer A drove 120 miles and paid $89, while Customer B drove 200 miles and paid $129. What is the per-mile rate the company charges?
  16. Use the factored form P(x)=x(x−2)2(x+1)P(x)=x(x-2)^2(x+1) to answer: What are the x-intercepts, and how does the graph behave at each intercept (crosses vs touches)?
  17. Complete the square to show that f(x)=−x2+14x−30f(x)=-x^2+14x-30 has a maximum, and find the maximum value.
  18. How many terms are in the expression 2x3−5x2+x−92x^3-5x^2+x-9?
  19. Which statement correctly describes 0×i0\times i where ii is an irrational number?
  20. Factor x2−10x+25x^2-10x+25 by recognizing it as a perfect square trinomial.

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