Hello!
Let
y be the total fee, and
x the number of months.
Equation 1:
y = 50 + 55 x
Equation 2:
y = 200 + 45 x
Solve the system for x and y.
50 + 55 x = 200 + 45 x
10 x = 150
x = 15
y = 200 + 45 (15)
y = 875
The total amount paid to both gyms is equal after
15
months and will be
$ 875
Hopefully this helps!