Question

What is the width in ... meters?

Answer 1

x - 12 meters.

Explanation:

Area = length * width

x^2 - 144 = (x + 12) * W where W = the width

W = (x^2 - 144)/ (x + 12)

= (x + 12)(x - 12) / (x + 12)

= x - 12 (answer).

Note that x^2 - 144 is an example of the difference of 2 squares , like

a^2 - b^2 which equals (a + b)(a - b).

Answer 2

use the formula
`(a-b)(a+b)=a^2-b^2\\`

In the rectangle, the area is L*w

(x-12)(x+12)=x^2-144

So, the expression which represents the width is x-12