Question

A rectangle with an area of 3990 cm2 is x centimeters wide and (x+4) centimeters long. To the nearest tenth of a centimeter, the width and length are

Answer 1

Answer: width:60.2 cm

Length: 64.2 cm

Explanation:

Given

The area of the rectangle is
`3990\ cm^2`

Width of the rectangle is
`x\ cm`

Length of the rectangle is
`x+4\ cm`

Area of the rectangle is the product of length and width

`\therefore 3990=(x+4)x\\\Rightarrow 3990=x^2+4x\\\Rightarrow x^2+4x-3990=0\\\Rightarrow x=60.198\ or\ -65.198\ cm\\\text{Neglecting negative term}\\\Rightarrow x=60.198\approx 60.2\ cm`

Width of the rectangle is
`60.2\ cm`

Length of the rectangle is
`60.2+4=64.2\ cm`