The length of a rectangle is 2 more than its width. If the area of the rectangle is 20m squared, what are the dimensions of the rectangle, to the nearest tenth of a metre?

L=2+W

A=LW

A = (2+W) W

20=2W+W^2

0=W^2+2W-20

use quadratic

fr

aw^2+bw+C=0

w = (-b+/-sqrt (b^2-4ac)) / 2a

a=1

b=2

c=-20

w = (-2+/-sqrt (2^2-4 (1) (-20))) / 2 (1)

w = (-2+/-sqrt (4+80)) / 2

w = (-2+/-sqrt (84)) / 2

w = (-2+/-2sqrt (21)) / 2

w=1+/-sqrt (21)

aprox

w=-3.58 or 5.58

cannot have negative width

w=5.58

round

w=5.6

sub

l=2+w

l=2+5.6

l=7.6

legnth=7.6m

width=5.6m