Question

The length of a rectangle is 7 meters more than four times its width if the area of the rectangle is 650 square meters, find the length and the width. round to nearest tenth

Answer 1

Let the width be x.
Width = x
Length = 4x + 7

The area is 650 m²

x(4x + 7) = 650
4x² + 7x - 650 = 0

Using quadratic formula:

`x = (-b \pm √(b^2 - 4ac) )/(2a)`

a = 4, b = 7, c = -650


`x = (-7 \pm √(7^2 - 4(4)(-650) )/(2(4))`


`x = 11.9 \ or\ x = -13.7 \text {(rejected, length cannot be negative)}`

Width = 11.9m
Length = 4(11.9) + 7 = 54.6m

Answer: Length = 54.6m and width = 11.9m