Math Help - Solving systems of linear equations

1. Solving systems of linear equations

A thorough explanation and step by step process would help me greatly. I do not know how to solve this problem.

Club A charges a $200 initial fee, plus$15 a month. Club B charges a $100 initial fee, plus$20 a month. The costs of belonging to the clubs can be compared using the following equations:

Club A: C = 200 + 15m
Club B: C = 100 + 20m

a) Find the point of intersection of the two lines.
b) After how many months are the costs the same?

Any help is appreciated. Thanks.

2. Set the two costs equal to eachother....

can you solve 200+15m=100+20m, if you can you will have your answer to part b) and for part a) you take the value of "m" that you find and plug it into either cost equation (as they produce the same number at the point of intersection) and find C