Question 670726
D=RT
300=XT
T=300/X
AND:
300=(X+10)(T-1)
300=(X+10)[(300/X)-1]
300=300-X+3000/X-10
0=-X+3000/X-10 MULTIPLY BY -X.
X^2-3000+10X=0
X^2+10X-3000=0
(X-50)(X+60)=0
X-50=0
X=50 MPH. ANS. 
300=50T
T=300/50
T=6 HOURS ANS.
300=(50+10)(6-1)
300=60*5 60 MPH. FOR 5 HOURS FOR THE FASTER CAR.
300=300