w=9
The room has dimensions of w w+3 so its area is w(w+3)=

The hallway has dimensions of w−3 so its area is 2w(w−3) =

If the room and hallway have the same area, then


w(w-9) = 0 , Factors
Since w is a dimension of the room, then w>0 so w=0 cannot be the value of w. Therefore w=9
.