Answer:
A. 5L + 3S = 135
7L + 9S = 255
B. Each small box weighs 13.75 kg
Each large box weighs 18.75 kg
Step-by-step explanation:
Part A:
Weight of each large box = L
Weight of each small box = S
✔️First Delivery:
Weight of 5 large boxes = 5L
Weight of 3 small boxes = 3S
Total weight = 135 kg
Equation that represents this would be:
5L + 3S = 135 ----› Eqn. 1.
✔️ Second Delivery:
Weight of 7 large boxes = 7L
Weight of 9 small boxes = 9S
Total weight = 255 kg
Equation that represents this would be:
7L + 9S = 255 ----› Eqn. 2
✔️System of equations would be:
5L + 3S = 135
7L + 9S = 255
Part B:
To find how much each box type weigh, solve simultaneously to find L and S.
5L + 3S = 135 ----› × 7
7L + 9S = 255 ----› × 5
35L + 21S = 945
35L + 45S = 1,275
Substraction
-24S = -330
Divide both sides by -24
S = 13.75
Each small box weighs 13.75 kg
Substitute S = 13.75 in eqn. 1 to solve for L
5L + 3(13.75) = 135
5L + 41.25 = 135
5L = 135 - 41.25 (subtraction property of equality)
5L = 93.75.
Divide both sides by 5
L = 18.75
Each large box weighs 18.75 kg
