Answer: $10
Step-by-step explanation:
Angie buys = 1 software package and 1month of gameplay.
Kenny buys = 1 software package and 2 months of game play.
Cost of each software package = $30. Total cost = $90
The total cost is the addition of what Kenny and Angie bought. This will be:
(1 SF + 1 G) + (1 SF + 2 G) = 90
where,
SF = software package = 30
G = game
(1 SF + 1 G) + (1 SF + 2 G) = 90
30 + 1G + 30 + 2G = 90
60 + 3G = 90
3G = 90 - 60
3G = 30
G = 30/3
G = 10
One month of game play cost $10