help math is not my strong suit

Question

there are two phone plans one plan has 28 one time fee and the cost 9 cents per minute the second plan is 13 cents per minute (no one time fee) how many minutes use will make plans cost the same

Answer 1

You can write two equations

Let m be minutes

The first plan = 9m +28

Second plan = 13m

Set them equal

9m+28=13m

Subtract 9m from both sides

28=4m

Divide both sides by 4

m=7

The answer is 7 minutes