c = 5 + 2r
You can go on 5 rides.
First, create the expression for the cost.
c = ?
Since the price of admission is $5, that becomes a term in the expression, so the new expression is:
c = 5 + ?
And since you need to pay for each ride (r) that also becomes a factor in the expression. Giving you:
c = 5 + 2r + ?
There isn't anything else that costs you money, so you can get rid of the placeholder of + ? giving you a final expression of
c = 5 + 2r
Now you need to figure out how many rides you can go on for $16. Lets figure it out.
You first have to subtract the price of admission. So you get
16 - 5 = 11
So after being admitted, you now have $11 in which to pay for rides. Since each ride costs $2, simply divide 11 by 2.
11 / 2 = 5.5
Since you really can't go on half a ride, that means you can go on 5 rides after being admitted to the park.
