Answer:
$3.8
Explanation:
What is the cost of a medium drink?
Let medium drinks = x
Large popcorn = y
At the movies, a couple bought 2 medium drinks and a large popcorn for $13.85.
2x + y = 13.85...Equation 1
y = 13.85 - 2x
At the same theater, a family bought 3 medium drinks and 2 large popcorns for a total of $23.90.
3x + 2y = 23.90.... Equation 2
Substitute y = 13.85 - 2x
3x + 2(13.85 -2x) = 23.90
3x + 27.7 - 4x = 23.90
3x - 4x = 23.90 - 27.7
-x = -3.8
x = $3.8
Since x = medium drink, the cost of a medium drink = $3.8