Question 701084
50+.20x<20+.50x
.20x-.50x<20-50
-.30x<-30
x>-30/-.30 not the change in the < sign. It changes to a > sign 
when dividing by a negative value.
x>100 miles makes Basic Rental a better deal.
Proof:
Let the mileage be 101 miles.
50+.20*101<20+.50*101
50+20.20<20+50.50
70.20<70.50