SOLUTION: During rush hour, Adriana can drive 20 miles using the side roads in the same time that it takes to travel 15 miles on the freeway. If Adriana's rate on the side roads is 10 mi/h

Algebra ->  Expressions-with-variables -> SOLUTION: During rush hour, Adriana can drive 20 miles using the side roads in the same time that it takes to travel 15 miles on the freeway. If Adriana's rate on the side roads is 10 mi/h       Log On


   

Question 71034: During rush hour, Adriana can drive 20 miles using the side roads in the same time that it takes to travel 15 miles on the freeway. If Adriana's rate on the side roads is 10 mi/h faster than her rate on the freeway, find her rate on the side roads.

Answer by checkley75(3666) About Me  (Show Source):
You can put this solution on YOUR website!
DISTANCE=RATE*TIME SO TIME=DISTANCE/RATE
20/(X+10)=15/X CROSS MULTIPLY
20X=15(X+10)
20X=15X+150
20X-15X=150
5X=150
X=150/5
X=30 MPH ON THE FREEWAY THUS
30+10=40 MPH ON THE SIDE ROADS.