Mat 171
PreCalculus Algebra

Solve the problem.
1) A car rental company has two rental rates. Rate 1 is $42 per day plus $.14 per mile. Rate 2 is $84 per day plus $.07 per mile. If you plan to rent for one day, how many miles would you need to drive to pay less by taking Rate 2?

For the pair of functions, find the indicated composition.
2) f(x) = 4×2 + 5x + 6, g(x) = 5x – 8
Find (g ∘ f)(x).

Use a graphing calculator to find the zeros of the function. Round to three decimal places. Include ALL Pictures of the Calculator Screen Showing Your Work Step By Step.
3) f(x) = x2 + 8x – 10

Solve the problem.
4) Assume that a person’s threshold weight W, defined as the weight above which the risk of death rises dramatically, is given by W(h) =, where W is in pounds and h is the person’s height in inches. Find the threshold weight for a person who is 6 ft 4 in. tall. Round your answer to the nearest pound.

Solve.
5) Suppose that $4000 is invested at an interest rate of 5.8% per year, compounded continuously. What is the balance after 3 years?

6) A cruise boat travels 24 miles downstream in 3 hours and returns to its starting point upstream in 6 hours. Find the speed of the stream.