The admission fee to the Fair is $7.50
The rides cost 50c each.
Let x be the number of rides she can take.
You can express her expenses in the fair as an equation:
C= total cost
C=7.50+0.5x → from this equation you can calculate how many rides she will be able to get on.
If she has a total of $23 to spend, then the number of rides can be calculated as:
With $23 she will be able to go on 31 rides.