Question

A phone company charges a base fee of $12 per month plus an additional charge per minute. The monthly phone cost C can be represented by this equation: C=12+a⋅m, where a is the additional charge per minute, and m is the number of minutes used.

Which equation can be used to find the number of minutes a customer used if we know a and C?

A
m=C−12a

B
m=(C−12)−a

C
m=C−12a

D
m=Ca−12

Answer 1

It’s actually m = (C - 12) /3 But I don’t see it in the 4 option you have.

Explanation:

C = 12+ am

C - 12 = am

(C - 12) /a = m

Answer 2

beside in this equation where C=$12 a= the additional charges and m= minutes used the equation would be C m=C-12a