Question

If an area of a rectangle is 56 cm. The length is 2 cm more than x. And the width is 5 cm less than twice the length. What is x

Answer 1

A=(x+2)(2x+4-5)

A=(x+2)(2x-1)

A=2x^2-x+4x-2

A=2x^2+3x-2, and A=56 so

2x^2+3x-2=56

2x^2+3x=58

x^2+1.5x=29

(x+0.75)^2=29.5625

x+0.75=±√29.5625

x=-0.75+√29.5625   (only the positive root is valid as dimensions must be positive)

x≈4.69 (to nearest one-hundredth)