After driving x miles, the first plan costs
60 + 0.70x
dollars, while the second plan costs
0.80x
dollars.
The plans cost the same when these prices are equal:
60 + 0.70x = 0.80x
Solve for x :
60 = 0.80x - 0.70x
60 = 0.10x
x = 60/0.10
x = 600
