Answer:
24
Step-by-step explanation:
Just plug each number in calculator and do multiply buy 3 and divide by 4 then add them together
Answer:$0.55
Step-by-step explanation:
Why do math got to be so complicated
Answer: 
<u>Step-by-step explanation:</u>

NOTE: The sign between 4x and 7 is missing in the question you posted. I assumed it was 4x + 7 in order to solve the equation.
A = L * W
A = 80
L = 5W
80 = W(5W)
80 = 5W^2
80/5 = W^2
16 = W^2
sqrt 16 = W
4 = W <=== width is 4 ft
L = 5W
L = 5(4)
L = 20 <=== length is 20 ft