Answer:
The equation is f = z - x
Explanation:
The equation is 
Given that 
The total cost + online fee for one ticket is $32.25
Let us assume f be the cost of ordering each ticket online 
Cost of each ticket be x = $24.95
And, the total cost = z = $32.25
Now the equation would be 
x + f = z
So for f it would be 
f = z - x