Answer:
I can only make an equation
20+30(4)+y(z)=X
Explanation:
SO we know the registration fee is 20 dollars so that can’t change
We know that its 30 dollars for up to 4 visits so 30*4
THe Y is for the amount it take to ski after the 4 times
The Z is for the amount of times you went after the 4 times
So yeah