After a baseball game, both the winning and losing teams went to the same fast food restaurant. the winning team bought 24 hamburgers and 18 orders of french fries for a total cost of $88.50.
the losing team bought 28 hamburgers and 9 orders of french fries at the same restaurant for a total cost of $88.25.
what is the cost of one hamburger at this restaurant?
$

The answer is $2.75

h - the cost of hamburgers
f - the cost of french fries

The winning team bought 24 hamburgers and 18 orders of french fries for a total cost of $88.50:
24h + 18f = 88.50

The losing team bought 28 hamburgers and 9 orders of french fries at the same restaurant for a total cost of $88.25:
28h + 9f = 88.25

This is the system of two equations:
24h + 18f = 88.50
28h + 9f = 88.25

Multiply the second one by (-2):
24h + 18f = 88.50
28h * (-2) + 9f * (-2) = 88.25 * (-2)

24h + 18f = 88.50
-56h - 18f = -176.50

Sum equations:
24h - 56h + 18f - 18f = 88.50 - 176.50
-32h = -88
h = -88/-32
h = $2.75