Answer:
The required length is 20 feet.
Step-by-step explanation:
Let the length be = L
Let the width be = W
The length of a rectangular floor is twice its width.
This becomes: [tex]L=2W[/tex]
The length of the carpet is L
As given the carpet width is 2 feet less than the room, so [tex]W=W-2[/tex]
Area of the carpet is given as = 160 square feet
So, Area becomes:
[tex]L(W-2)=160[/tex]
As L=2W, we get;
[tex]2W(W-2)=160[/tex]
=> [tex]2W^{2} -4W-160=0[/tex]
Taking out 2 common, we get;
[tex]W^{2} -2W-80=0[/tex]
Solving this quadratic equation, we get:
(W-10) and (W+8)
Hence, W = 10 and W = -8(neglect this negative value)
Now, the width = 10 feet
And Length = [tex]2\times10=20[/tex] feet
So, the required length is 20 feet.