Question

Joe will rent a car for the weekend. He can choose one of two plans. The first plan has no initial fee but costs
$0.90
per mile driven. The second plan has an initial fee of
$65
and costs an additional
$0.40
per mile driven. How many miles would Joe need to drive for the two plans to cost the same?

Answer 1

let m be the number of miles

case1: cost = .9m
case2: cost = 65 + .4m

so you want :
.9m = 65 + .4m
.5m = 65
m = 130

Answer 2

550