Answer:
The cost of slices of pizza = x = $2.82
The cost of garlic knots = y = $0.55
Explanation:
David and joe went to the pizzeria.
Let
The cost of slices of pizza = x
The cost of garlic knots = y
David ordered 3 slices of pizza and 4 garlic knots and paid 10.65.
3x + 4y = 10.65....Equation 1
Joe ordered 2 slices of pizza nd 10 garlic knots and paid 9.30.
2x + 10y = 9.30.... Equation 2
Hence:
3x + 4y = 10.65....Equation 1
2x + 10y = 9.30.... Equation 2
We solve using Elimination method:
Multiply Equation 1 by 2 and Equation 2 by 3 to eliminate x
3x + 4y = 10.65....Equation 1 × 2
2x + 10y = 9.30.... Equation 2 × 3
6x + 8y = 21.30.....Equation 3
6x + 20y = 27.9...Equation 4
Subtract Equation 4 from 3
12y = 6.6
y = $0.55
We solve for x using Equation 1
3x + 4y = 10.65....Equation 1
3x + 4($0.55) = $10.65
How much is the cost of each item
3x + $2.2 = $10.65
3x = $10.65 - $2.2
3x = $8.45
x = $8.45/3
x = $2.8166666667
x = $2.82
The cost of each items
The cost of slices of pizza = x = $2.82
The cost of garlic knots = y = $0.55