Posted by JIM on .
You commute 56 miles one way to work. The trip to work takes 10 minutes longer than the trip home. Your average speed on the trip home is 8 miles per hour faster. What is your average speed on the trip home?
I got to this point
xy=56
(x8)(y+10)=56
I couldn't get any further than that. I'm not sure where to go with those equations.

Algebra 
bobpursley,
Ok, then x=56/y
(56/y 8)*(y+10/60)=56
multiply both sides by y.
y(56/y 8)*(y+10/60)=56y
(56 8y)*(y+10/60)=56y
FOIL that, and solve the quadratic for y. ONce you get that, you can solve for x.
Note:
The fraction 10/60 is important..the ten was in minutes, and it has to be converted to hours, as speed was given in km/hr (remember the units given for 8).