help with math problem

Question

a country music station has 200 regular listeners and each month gains 12 more. Another station has 300 regular listeners and each month gains 8. in how many months will the two stations have the same number of regular listeners?

Answer 1

y = mx + b

y = 12x + 200

y = 8x + 300

Let the y's be equal as they represent the number of viewers

12x + 200 = 8x + 300

4x = 100

x = 25 months