Help with a word problem

Question

Suppose you have entered a 157 mile biathlon that consist of a run and a bicycle race. During your run, your average velocity is 8 miles per hour, and during your bicycle race, your average velocity is 25 miles per hour. You finish the race in 9 hours. What is the distance of the run? What is the distance of the bicycle race?

Answer 1

157= 8x +25(9-x)

=8x-25x +225=157

17x = 68

x=68/17= 4 hours running, 9-x=5 hours biking

run 4(8)=32 miles

bike 5(25)=125 miles