Find Area in term of X

Question

Rectangular Pen A rectangular pen has a perimeter of 100 feet. If x represents its width, write a polynomial that gives the area of the pen in terms of x.

Answer 1

For your rectangle, let's assume x is the width and y is the height.

P = 100 = 2x + 2y

Because y is in this equation, we can find what it equals in terms of x.

y = (100 - 2x)/2

A = x y

Substitute in what we just found for y.

A = x ((100-2x)/2))

Note: You could distribute the x, making A = (100x - 2x²)/2.