Question

A rectangular swimming pool has length (x + 4) meters and width (x - 2) meters. The area of the

pool is 72 square meters. The length of the pool is ----- meters.
12
4.
8
16

Answer 1

The length if the pool is 12

Explanation:

Formula: A=lw or lw=A

> (x+4)(x-2)=72

> (x²-2x+4x-8)=72

> x²+2x-8=72

> x²+2x-8-72=0

> x²+2x-80=0

Factor

> x²+10x-8x-80

> x(x+10)-8(x+10)

>(x+10)(x-8)

Check:

(x-4); (x-2); x=8

(8+4)=12 Length

(8-2)=6 Width