You are trying to find the values of two quantities, so you will need to set up a system of two equations in two variables. We'll call M the price of a move and V the price of a video game.
The first month: 9 movies, 7 video games, $56. Let's translate this into algebra:
9M + 7V = 56
The second month: 3 movies, 5 video games, $72. Translated:
3M + 5V = 34
Solve that system of equations.
