Acell phone company has a basic monthly plan of $40plus $0.45 for many minutes ised over 700. john was charged a total of $48.10. write an equation to determine how many minutes he must have used during the month.

Cost of month plan = $40

Cost of minutes used = $0.45 after 700 minutes

Total cost = $48.10

Let x be the total minutes used
Total cost = 40 + 0.45(x - 700)


Form the equation and solve x

40 + 0.45(x - 700) = 48.10
40 + 0.45x - 315 = 48.10
0.45x - 275 = 48.10
0.45x = 48.10 + 275
0.45x = 323.10
x = 323.10 ÷ 0.45
x = 718


John had used 718 mins this month