Answer:
f(m) = 75-8m
Step-by-step explanation:
She began with $75. After the first movie, she had $67 remaining; this means she spent
75-67 = $8
After the second movie, she had $59 remaining; she spent
67-59 = $8
After the third movie, she had $51 remaining; she spent
59-51 = $8
Each movie costs $8. Letting m represent the number of movies, this gives us 8m.
Since she is spending money, we subtract this from the original amount, $75; this gives us
f(m) = 75-8m