Question

The length of a rectangle is 4 m more than the width the area of the rectangle is 45m^2 find the length and width

Answer 1

l=w+4m
A=w*l
A=w(w+4)=45
w^2+4w-45=0
w^2+9w-5w-45=0
w(w+9)-5(w+9)=0
(w+9)(w-5)=0

⇒ w+9=0 or w-5=0
⇒w-5=0
w=5
l=5+4
l=9