25.50 = 7d + 2p
52.50 = 5d + 10p
These are the two equations we're going to use to determine the price of popcorn.
First we need to eliminate one set of variables. Let's eliminate the drinks.
127.50 = 35d + 10p
-367.50 = -35d + -70p
-240 = 0d - 60p
-240 = -60p
P = 4.00
So, popcorn is $4, right? Let's keep working on the problem so we can double check...
So, now let's add the $4 as the variable for P.
25.50 = 7d + 8
52.50 = 5d + 40
17.50 = 7d
12.5 = 5d
d = 2.5
d=2.5
This checks out! Since both equations state that drinks are 2.50, that means we have the right pricing for popcorn... $4.00
Popcorn is $4.00, drinks are $2.50
<em>Hope I could help! :) </em>