On a weekend outing, Charles rents a motorboat for 8 hours to travel down the river and back. The rental operator tells him to go for 3 hours downstream, leaving 5 hours to return upstream.

Question

On a weekend outing, Charles rents a motorboat for 8 hours to travel down the river and back. The rental operator tells him to go for 3 hours downstream, leaving 5 hours to return upstream.

If the River current flies at a speed of 7 mph, how fast must Charles travel in order to return in 8 hours?

Answer 1

d = 5(r - 7)

d = 3(r + 7)

Can you solve for r and answer?