Question 488769
Hey, 
So for this one we need to see what we know and figure it out from there:
First, we know that the area of the rectangle is 18 in^2. This means that the length (L) multiplied by the width (W) equals 18. In other words, L x W = 18. 
Second, we know that the length (L) is twice the width (W). In other words, L = 2W. 
We can use this last bit of information by substituting 2W in the area equation for L:
(2W) x W = 18 => 2W^2 = 18 => (2W^2)/2 = 18/2 => W^2 = 9 => W = 3. Now we can substitute 3 for W in the other equation:
L = 2(3) => L = 6.
Therefore,
L = 6, W = 3
I hope this helps!