Question

The area of rectangle RSTU is 36x2+25x−25. The length of the rectangle RSTU is 4x+5. Which expression describes the width of the rectangle RSTU?

Answer 1

Given:

The area of the rectangle RSTU = $36x^2+25x-25$

Length of the rectangle RSTU = $4x+5$

To find:

The width of the rectangle RSTU.

Step-by-step explanation:

We have,

$36x^2+25x-25$

Splitting the middle term, we get

$=36x^2+45x-20x-25$

$=9x(4x+5)-5(4x+5)$

$=(4x+5)(9x-5)$

We know that, the area of a rectangle is

$Area=Length \times width$

Area of rectangle is product of (4x+5) and (9x-5).

Since (4x+5) is the length of the rectangle, therefore, (9x-5) is the width of the rectangle RSTU.