SOLUTION: The perimeter of a rectangle is 80 feet. Express its area, A as a function of the length x of a side.

Question 1043662: The perimeter of a rectangle is 80 feet. Express its area, A as a function of the length x of a side.
Answer by ikleyn(52886) (Show Source): You can put this solution on YOUR website!
.

Let L be the length of the rectangle, and W be the width.


Then L + W + L + W = P, perimeter, or  2*(L+W) = P,  or  L + W =  =  = 40 feet.

Hence, W = 40 -L.

The area of the rectangle is equal to 

A = L*W = L*(40-L) = .

So, A =  expresses the area of the rectangle as the function of L.

Solved.

You can find many simple solved introductory problems on area of rectangle in the lesson
- Problems on the area and the dimensions of a rectangle
in this site.

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