1. A-Tunes requires a membership fee of $12 a month and $1 for each download.
Bapstar requires a membership fee of $5 a month but charges $1.50 for each
download. When do the charges for the two companies equal each other?

After 16 downloads the charges will equal each other.

First set up an equation

x = Downloads

12 + 1x = 5 + 1.5x

Solve

12 + 1x = 5 + 1.5x <- Rewrite your equation

-5          -5            <- Subtract 5 from both sides

 8 + 1x = 1.5x       <- Simplify

      -1x    -1x         <- Subtract 1 from both sides

        8 = 0.5x      <- Simplify

        8 = 1/2x       <- Convert 0.5 to a fraction to make the next step easier

       16 = x            <- Multiply both sides by 2 to divide by

                                 a fraction

this answer is !