Question

the area on the wall covered by a rectangle is 320 square inches. The length of the poster is 1.25 times longer than the width of the poster. What are the dimensions of the poster?

Answer 1

To answer this question you will think of the length and the width as the following:
Length- 1.25w
Width-w

Using this you can then substitute in the information in your formula for finding the area of a rectangle.

A = lw
320 = 1.25w(w)
320 = 1.25 w^2; divide both sides by 1.25

256 = w^2; find the square root of both sides

w = 16 in

l = 1.25 x 16
l = 20 inches

The dimensions are a width of 16 inches and a length of 20 inches.