You are creating a rectangular banner for a school pep rally. You have 100ft^2 of paper and you want 15ft. longer than the width. What should the dimensions of the banner be?

You are given the area of the rectangle which is 100 ft^2.

We know that the area of a rectangle is given by length x width.

It is also given that L = W + 15 (because you want the rectangle to be longer)

So substituting the values, we have:

W (W+15) = 100

W² + 15W - 100 = 0

(W+20) (W-5) = 0

W = - 20; W = 5

(-20 is an extraneous solution)

Solving for L:

L = 5 + 15 = 20

The dimensions of the rectangle is 20 ft by 5 ft.