Answer:
Shipping Cost of small boxes = x = $7
Shipping Cost of large boxes = y = $15
Step-by-step explanation:
Let us represent
Shipping Cost of small boxes = x
Shipping Cost of large boxes = y
The postal service offers flat-rate shipping for priority mail in special boxes.
Today, Kylie shipped 4 small boxes and 4 medium boxes, which cost her $88 to ship.
4x + 4y = 88...... Equation 1
Meanwhile, Trevor shipped 9 small boxes and 4 medium boxes, and paid $123.
9x + 4y = 123 ..... Equation 2
Combining both Equations
4x + 4y = 88...... Equation 1
9x + 4y = 123 ..... Equation 2
Subtract Equation 1 from Equation 2
5x = 35
x = 35/5
x = $7
Solving for y using Equation 1
4x + 4y = 88...... Equation 1
4($7) + 4y = 88
28 + 4y = 88
4y = 88 - 28
4y = 60
y = 60/4
y = $15
Shipping Cost of small boxes = x = $7
Shipping Cost of large boxes = y = $15
