Question

2. 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 # of minutes a customer used if we know and a and C?
A. m = (C-12)
B. m = (C - 12)-a
C. m = C - 12a
(C-12)
D. m =
a
E. m = 8-12

Answer 1

Given:

The monthly phone cost C can be represented by this equation:

`C=12+a\cdot m`

where, a is the additional charge per minute, and m is the number of minutes used.

To find:

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

Solution:

We have,

`C=12+a\cdot m`

We need to isolate m on one side.

Subtract 12 from both sides.

`C-12=a\cdot m`

Divide both sides by a.

`(C-12)/(a)=(a\cdot m)/(a)`

`(C-12)/(a)=m`

`m=(C-12)/(a)`

The options are not in proper format.

Therefore, the required equation is
`m=(C-12)/(a)`.