To solve this problem, we can define the following variables:
c: The number of commercials on which Sadie's songs were played
m: The number of movies on which Sadie's songs were played
With these variables, we can write the following system of equations:
c + m = t (1)
40c + 120m = 440 (2)
Where t represents the total number of commercials and movies on which Sadie's songs were played.
Equation (1) represents the total number of commercials and movies on which Sadie's songs were played, and equation (2) represents the total earnings from all commercials and movies.
To solve this system of equations, we can substitute the value for c in equation (1) into equation (2) to eliminate c. This gives us the following equation:
40(t - m) + 120m = 440
40t - 40m + 120m = 440
40t = 480
t = 12
Substituting this value for t back into equation (1) gives us the following equation:
c + m = 12
We can solve this equation to find the number of commercials and movies on which Sadie's songs were played. For example, if c represents the number of commercials, then m = 12 - c. If c = 5, then m = 7, and if c = 7, then m = 5.
Thus, the number of commercials and movies on which Sadie's songs were played can be represented by the system of equations:
c + m = 12
40c + 120m = 440
where c represents the number of commercials and m represents the number of movies.