the rectangular living room is calculated as length * width
The area is given to be equal to 40 sq. meters (area = 40 sq. meters)
Let the width = x meters
Length = X+3 meters
Area = Length * Width
40 = X * (X+3)
40 = X^2 + 3X
We solve this quadratic equation
So x = 5 or x= -8
Width cannot be negative, so we reject x =-8
So x = 5 is the answer
Width of the room = 5 meters