Algebra question

Question

meg rowed her boat upstream a distance of 96 mi and then rowed back to the strating point. the total time of the trip was 20 hours. if the rate of the current was 2 mph, find the average speed of the boat relative to the water

Answer 1

(s+2)(x) + (s-2)(20-x) = 96(2)

speed times time = distance

x = 96/(s+2)

(s-2)(20-x) = 96

(s-2)(20 - 96/(s+2)) = 96

multiply by s+2

(s-2)(20(s+2) - 96) = 96(s+2)

20s^2 -192s -80=0

5s^2 -48s -20 =0

s = 4.8 + 5.2 = 10 mph = boat's speed in still water