Question

A video rental store charges $4 per day to rent a movie and $3 per day to rent a video game. During one summer, Tony paid a total of $140 to rent movies and video games from this store. If he rented twice as many video games as movies, how much did he spend on movie rentals during the summer?

Answer 1

Let's use the variables m and v for this:
4m + 3v = 140
v = 2m
Insert this variable:
4m + 3(2m) = 140
4m + 6m = 140
10m = 140
m = 14
One movie costs 4 dollars:
14*4 = 56
He spent $56 on movies