Question

The area of a rectangle is 72 cm square. The length of the rectangle is 6 cm longer than the width. What is the width of the rectangle? A 2 cm B 6 cmC 8 cmD 10 cm

Answer 1

The correct option will be :  B) 6 cm.

Explanation

Suppose, the width of the rectangle is $x$ cm.

As, the length is 6 cm longer than the width, so the length will be: $(x+6) cm.$

Formula for the Area of rectangle is: $(Length)*(Width)$

Given that, the area of a rectangle is 72 cm²

So....

$x(x+6)=72\\ \\ x^2+6x-72=0\\ \\ (x+12)(x-6)=0$

Using zero-product property, we will get...

$x+12=0\\ x= -12$ (Negative value is ignored as width can't be negative)

and

$x-6=0\\ x=6$

So, the width of the rectangle is 6 cm.