math
posted by simon .
the distance between 2 station A and B is 230 km .two car start simultaneously from A and B in the opposite directions and the distance between them after 3 houra is 20 km. If the speed of one car is less than that of the other by 10 km per hour, find the speed of each cars. (equation)

Let x and y be the two speeds, x>y.
First part:
after 3 hours of driving towards each other, the distance is reduced from 230 to 20, so
3(x+y)=23020
x+y=70
Speed of one is 10 km less than the other:
xy=10
We have a sum and difference problem where the solution is
x=(sum+difference)/2=40
y=(sum=difference)/2=30 
pot it.

Thanks a lot