HELP!!!

Equations:
Horizon Wireless: y=0.40x+55
Firefly Wireless: y=0.15x+80

How many minutes (x) would you have to use for the total cost (y) of both cell phone plans to be the same?

Respuesta :

0.40x + 55 = 0.15x + 80
0.40x - 0.15x = 80 - 55
0.25x = 25
x = 25 / 0.25
x = 100 minutes <=