Answer:
9
Step-by-step explanation:

Answer:
81 cm^2
Step-by-step explanation:
Side = perimeter / 4 = 36/4 = 9 cm
area = side^2 = 9^2 = 81 cm^2
Answer:
G - number of arrangements
F. the amount of her allowance
B. y = x
H. the number of hours
Answer:
21 kWh
Step-by-step explanation:
1. Subtract 25% from the original amount.
25% of 28 kWh is ...
0.25 × 28 kWh = 7.00 kWh
Subtracting this from 28 kWh, we find the usage after reduction to be ...
28 kWh - 7 kWh = 21 kWh
__
2. We know that if we reduce 100% of a quantity by 25%, then the resulting amount is (100 -25)% = 75% of the original. As a fraction, this is 75/100 = 3/4 of the original amount. Then the reduced usage is ...
(3/4) × (28 kWh) = 3·(7·4)/4 kWh = 3·7 kWh = 21 kWh
__
Mario must reduce his usage to 21 kWh or less.