Question 549280
50+.20X<20+.50X
.20X-.50X<20-50
-.30X<-30
X>-30/-.30 

NOTE: THE SIGN CHANGES WHEN DIVIDING BY A NEGATIVE VALUE.
X>100 GREATER THAN 100 MILES DRIVEN MAKES THE BASIC RENTAL OFFER A BETTER DEAL.
PROOF:
50+.20*100<20+.50*100
50+20<20+50
70<70