Question 535008
Distance(d) equals Rate(r) times Time(t) or d=rt; r=d/t and t=d/r
t=d/r
t=100/x hours-----time required to drive 100 mi at x mph
So amount of gas used =(100+x^2)gal/hr times (100/x) hr
(100+x^2)(100/x)=100(100+x^2)/x gal

Hope this helps---ptaylor