What is the area of a rectangular sign when the base is 20 ft less than 4 times the height, h

Express the area of the sign as a function of h.

A=B times H

So B = 20-4H

Now Area = (20-4H) times H

Make sure to use order of operations

first step. rewrite the words as an expression:
A = bh, A is the area; b is the base; h is the height
b = [an expression involving h]
second step
substitute the expression for b in the original area formula