Question

A phone company charges a base fee of $12 per month plus an additional charge per minute. The monthly phone cost 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 C and a?

a. m = (C/a) - 12
b. m = C - 12a
c. m = (C - 12) - a
d. m = (C - 12)/a

Answer 1

The equation that can be used to find the number of minutes a customer used if we know C and a is m = (C - 12)/a.

Step-by-step explanation:

The equation that can be used to find the number of minutes a customer used if we know C and a is m = (C - 12)/a.

To derive this equation, we start with the given equation: C = 12 + a * m.

First, we subtract 12 from both sides of the equation to isolate a * m: C - 12 = a * m.

Then, we divide both sides of the equation by a to solve for m: m = (C - 12)/a.