At the movies, a couple bought 2 medium drinks and a large popcorn for $13.85. At the same theater, a family bought 3 medium drinks and 2 large popcorns for a total of $23.90. What is the cost of a medium drink?

$3.8

Step-by-step 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