SOLUTION: Raul found that by increasing his speed by 5 km/hr, he could drive 12km in 0.2 hrs. What was his original speed? ____kilometers per hour thanx

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: Raul found that by increasing his speed by 5 km/hr, he could drive 12km in 0.2 hrs. What was his original speed? ____kilometers per hour thanx      Log On


   

Question 39978: Raul found that by increasing his speed by 5 km/hr, he could drive 12km in 0.2 hrs. What was his original speed?
____kilometers per hour
thanx
Answer by Paul(988) About Me  (Show Source):
You can put this solution on YOUR website!
EQUATION:
12%2Fx-12%2F%28x%2B5%29=0.2
12[(x-x+5)]=0.2[(x)(x+5)]
60=0.2x%5E2%2Bx
x%5E2%2B5x-300=0
x%5E2%2B5x-300=0
Solve tha you get x=15
Hence, he drives at 15mph.
paul.