Speedy Carz :
Flat fee: $45
Cost per mile: $0.75
x= number of miles
Cost of Speedy Carz= 0.75x+45
Affordable autos;
Flat fee: $24
Cost per mile: $1.25
Cost of Affordable autos: 1.25x+24
If both costs are the same:
Cost of Speedy Carz=Cost of Affordable autos
So:
0.75x+45=1.25x+24
Solve for x:
45-24 = 1.25x-0.75x
21= 0.5x
21/0.5=x
x= 42 miles
To calculate the cost when that number of miles are driven, replace x on any equation:
0.75x+45
0.75(42)+45
31.5+45
$76.5