Angie buys 1 software package and 3 months of game play Kenny buys 1 software package and 4 months of game play price of each software package = $20 total cost = $117 cost of one month game play = ? let y is the cost of one month play Angie buys 3 months game play and paid $20 = 20 + 3y Kenny buys 4 months game play and paid $20 = 20 + 4y total cost of both is $117 So the equation becomes, (20 + 3y) + (20 + 4y) = 117 7y + 40 = 117 7y = 117 - 40 7y = 77 dividing with 7 on both sides, we get y = 11 so, $11 is the cost of one month game play
I think the part he has correct is when they are equal because they intersect at a coordinate, but, he is incorrect because the teacher's expression could be different
