Chapter 8.4, Problem 252E

Kayaking When Trina kayaks upriver, it takes her $\frac{5}{3-c}$ hours to go 5 miles, where c is the speed of the river current. It takes her $\frac{5}{3+c}$ hours to kayak 5 miles down the river.

a. Find an expression for the number of hours it would take Trina to kayak 5 miles up the river and then return by adding $\frac{5}{3-c}+\frac{5}{3+c}$

b. Evaluate your answer to part (a) when c = 1 to find the number of hours it would take Trina if the speed of the river current is 1 mile per hour.