Question

Shandra has a sheet of cardboard whose area is x2 + 2x − 15 square inches. We know that the length of the cardboard sheet is (x + 5) inches. What is its width? (Hint: area = length · width)

Answer 1

Given that area = length * width, where we know area and length. A simple division will do, x^2 + 2x - 15 / x + 5 = x - 3.

Answer 2

The width will be
`(x-3)\ inches.`

Explanation:

Area of the sheet of cardboard
`=(x^2+2x-15)\ square\ inches`

Length of the sheet
`=(x+5)\ inches`

We know,
`Area = Length * Width`

So,
`Width=(Area)/(Length)`

Thus....

`Width=(x^2+2x-15)/(x+5)\\ \\ =(x^2+5x-3x-15)/(x+5) \\ \\ =(x(x+5)-3(x+5))/(x+5)\\ \\ =((x+5)(x-3))/(x+5)=x-3`

So, the width will be
`(x-3)\ inches.`