Hello!
Let Â
y  be the total fee, and Â
x  the number of months.
Equation 1:
y  =  50  +  55 x
Equation 2:
y  =  200  +  45 x
Solve the system for  x  and y. Â
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 Â
15
months and will be Â
$ 875 Â
Hopefully this helps!