Question

The area of a rectangle is 12 square inches. The length is 5 more than twice the width. Find the length and the width

Answer 1

Let the width equal x, therefore the length is 2x+5. The area is length*width, so we know:

x(2x+5)=12
=> 2x^2+5x=12
=> 2x^2+5x-12=0
=> (2x-3)(x+4)=0

So we know x=-4, or x=1.5. Lengths can't be negative, so x=1.5.