Answer:
The cost of one brownie is $0.75
Explanation:
The given parameters are;
The number of pizza's Marcel bought = 4 pieces
The number of brownies Marcel bought = 2 brownies
The amount Marcel paid = $18.50
The number of pizza's Morgan bought = 3 pieces
The number of brownies Morgan bought = 2 brownies
The amount Morgan paid = $14.25
Let x represent the cost of a pizza and y represent the cost of a brownie, we have;
4·x + 2·y = $18.50...(1)
3·x + 2·y = $14.25...(2)
Subtracting equation (1) from equation (2) gives;
4·x + 2·y - (3·x + 2·y) = $18.50 - $14.25 = $4.25
4·x - 3·x + 2·y - 2·y = $4.25
x = $4.25
The cost of a pizza = x = $4.25
4·x + 2·y = $18.50
2·y = $18.50 - 4·x = $18.50 - 4×$4.25 = $1.5
y = $1.5/2 = $0.75
y = $0.75
The cost of a brownie = $0.75