Practice Test 26 - Algebra 1

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

  1. A teacher wants to describe how much time students spend on homework in a class (not predict future grades). Which variable definitions are most appropriate?
  2. A bacteria culture starts with 200 bacteria and grows by 10% each hour. Write a function P(t)P(t) for the population after tt hours. Write in the form P(t)=a(1+r)tP(t)=a(1+r)^t.
  3. Solve using substitution: {y=2x+1x+y=7\begin{cases} y = 2x + 1 \\ x + y = 7 \end{cases} Find the solution $ (x, y) $.
  4. If ff is linear, f(0)=4f(0)=4, and f(3)=13f(3)=13, what is f(x)f(x)? Write in the form f(x)=mx+bf(x)=mx+b.​
  5. A school club is ordering snacks for an event. Let xx be the number of boxes of granola bars and yy be the number of boxes of fruit snacks. Constraints: - Each granola box costs $6 and each fruit snack box costs $4. - The club can spend at most $60. - They need at least 12 boxes total. - They cannot order a negative number of boxes. Which system of inequalities models this situation?
  6. Factor x2−10x+25x^2-10x+25 by recognizing it as a perfect square trinomial.​
  7. If f(x)=2x+1f(x)=2x+1 and g(x)=x−3g(x)=x-3, which expression equals f(g(x))f(g(x))?
  8. A runner's distance from the starting line (in miles) after tt hours is given by d(t)=6t+2d(t)=6t+2. What is the average rate of change of d(t)d(t) from t=1t=1 to t=4t=4? Give your answer in mi/hr.
  9. A population of bacteria grows according to P(t)=1000⋅1.5tP(t) = 1000 \cdot 1.5^t where tt is time in hours. A chemical reaction produces a byproduct at a rate described by Q(t)=50t2+100tQ(t) = 50t^2 + 100t grams after tt hours. At t=3t = 3$ hours, P(3)≈3375P(3) \approx 3375 bacteria and Q(3)=750Q(3) = 750 grams. If these trends continue, what will happen over a long time period?
  10. A theater is choosing how many adult and student tickets to sell in advance for a small show. Let xx = number of adult tickets and yy = number of student tickets. Constraints: - The theater has at most 120 seats: x+y≤120x+y\le 120. - Adult tickets are $12 and student tickets are $8; advance sales revenue must be at least $1000: 12x+8y≥100012x+8y\ge 1000. - At least 30 student tickets must be available: y≥30y\ge 30. - x≥0x\ge 0 and y≥0y\ge 0. Is the point (70,40)(70, 40) a viable solution?
  11. Solve for yy in the literal equation ax+by=cax + by = c (treat aa, bb, and cc as constants).
  12. Solve for xx: 2(x−3)+5=152(x - 3) + 5 = 15
  13. Refer to the system of inequalities graphed below. A new constraint y≥x−2y \geq x - 2 is added to this existing system. How does this change the solution region?
  14. A water tank starts with 500 gallons and is drained at a constant rate of 25 gallons per minute. Express the remaining volume V(t)V(t) (in gallons) as a function of time tt (in minutes).
  15. Rewrite 2x2+7x+1x+3\frac{2x^2+7x+1}{x+3} in the form q(x)+r(x)x+3q(x)+\frac{r(x)}{x+3} (quotient plus remainder over divisor), where deg⁡(r)<1\deg(r)<1.​
  16. A water tank is being drained at a constant rate. After 12 minutes, the tank contains 450 gallons. After 20 minutes, it contains 330 gallons. Which equation can be used to find the time tt (in minutes) when the tank will be completely empty?
  17. Solve and check for extraneous solutions: 3x−1+2=5.\frac{3}{x-1}+2=5.
  18. The quadratic function is y=x2+6x+5y=x^2+6x+5. What is the y-intercept of y=x2+6x+5y=x^2+6x+5? (Give your answer as a point.)
  19. For f(x)=x3f(x) = x^3, what is f(−2)f(-2)?
  20. A town's population is modeled by the exponential function P(t)=800(1.03)tP(t)=800(1.03)^t, where tt is the number of years since 2020. What is the annual percent growth rate?

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