Answer: d) 12 ft
Step-by-step explanation:
Let x be the width of the room , the the length of the room will be 2x.
We consider the shape of room is rectangle.
We know that the area of rectangle is given by :-
[tex]A=l\times w[/tex], where l is length and w is width.
Given : Area of the room is 288 square feet
[tex]\Rightarrow 288=2x\times x\\\\\Rightarrow\ 2x^2=288\\\\\Rightarrow\ x^2=144\\\\\Rightarrow\ x=-\sqrt{144}=\pm12[/tex]
Since, width cannot be negative, so the width of the room = 12 feet.