Chelsey wants to join a fitness club. the fitness club charges an initial membership fee of $55 and a monthly fee of $19.50. she has $250 to spend. write and solve an equation to find the number of months she can be a member.

So if you have to pay 55 out front and then continue to pay 19.50 monthly the equation will look like this:
19.50*m + 55 = x
(M stands for month)
She has 250 dollars to spend so add that in for x
19.50*m + 55 = 250. 
Use inverse operations.
250-55 and 55-55
19.50*m = 195
195/19.50 and 19.50/19,50
m=10
Your answer is 10

Just tell koda to adjust the number of shapes himself.