From the following information in the problem, we construct the following equations: (assuming that we use m=movies and v=video games.)

1.7m+9v=78

2. 5m+3v=36

Using the method of substitution:

7m+5m+9v+3v=114

12m+12v=114

m+v=19/2

and so m=19/2-v.

Substituting this into equation 1, we get:

7(19/2-v)+9v=78

66.5+2v=78

2v=11.5

v=5.75 and so m=3.75