Programmers need to solve systems of equations, which often come up during the design of the games. As an example, suppose in a video game 2 persons (or objects) are traveling along linear paths, and you need to find the coordinates at which they might potentially collide. Suppose the two lines are 2x + 3y = 8 and 4x - y = -2. Solving the system of equations would give you the (x, y) coordinates of the possible collision.
Make a system of 2 equations with 2 variables of your own creation.