Alan and Dirk each want to run for president of their school's student body council. In order to do so, they must collect a certain number of signatures and get a nomination.
So far, Alan has 7 signatures, and Dirk has 5. Alan is collecting signatures at an average
rate of 2 per day, whereas Dirk is averaging 4 signatures every day.

1) Write a system of linear equations to represent this situation

2) graph that system

3) find the solution and explain what it means