106k views
9 votes
The area of a rectangle is x² + 2x -15. If its length is x + 2 units, what is its width?

User Webwurst
by
4.4k points

1 Answer

12 votes

Length of the rectangle is 8 units

Explanation:

  • Step 1: Find the length, let width be x.

Area of the rectangle = 48 units

Length = x + 2

⇒ Area = Length × Breadth

48 = x (x + 2)

48 = x² + 2x

x² + 2x - 48 = 0

x² + 8x - 6x + 48 = 0 (Product Sum rule to factorise)

x(x + 8) - 6(x + 8) = 0

(x - 6)(x + 8) = 0

⇒ x = 6, -8 (negative value is neglected)

∴ x = 6

x + 2 = 8

User Jon Wayne Parrott
by
4.7k points