D. It is not a function because there are multiple outputs for one input.
You could use a calculator. Other than that, I've never heard of an easier way to do long division.
First you have to simplify the equation. 7m+5m-5 = -5+12m
Then you can add like terms.
12m-5 = -5+12m
Add 5 to both sides
12m = 0+12m
Subtract 12 to both sides
0=0
This equation has infinite solutions
This should be the correct answer 3x2(2x2+4)

Is the simple answer, making The cost divided by the minutes. The answer is 2.33 (repeating 3s)