Two cars leave Kansas City at the same time.

Question

One car is moving east and the other west.
After 5 hours, the cars are 575 miles apart.
One car is traveling 15 miles per hour faster than the other.
Let S = the speed of the slower car and F = the speed of the faster car.
If one equation for this system is 5F + 5S = 575, what is the other? Type your answer without spaces.

I don't understand this problme its saying one is 15 mile faster
would'nt it be 15F+60S=575? If it's wrong please tell me what i did wrong and explain it.

Answer 1

5F + 5S = 575.
F = S+15.
5(S+15) + 5S = 575.

Answer 2

So it would be 5s+15s+5s=575?

Answer 3

hint:
5(S+15)=5*S+5*15 (distribution)
=5S+75