Smiley, let's change your problem a little, to this:

The length of a rectangle is twice its width. If we increase the length by 8 feet

and the width by 6 feet, the area is increased by 88 square feet.

What are the dimensions of the orignal rectangle?

Let width of original rectangle = w

Then length of original rectangle = 2w

So area of original rectangle = w * 2w = 2w^2 ; you ok with that :?:

length of new rectangle = 2w + 8 : right?

width of new rectangle = w + 6 : right?

So area of new rectangle = (2w + 8) * (w + 6) = 2w^2 + 20w + 48 : OK??

Since area of original rectangle is increased by 88, then:

2w^2 + 88 = 2w^2 + 20w + 48 : still with me?

so: 20w = 40 : w = 2

So width original rectangle = 2 and length = 4, right?

And width new rectangle = 2+6 = 8, length = 4+8 = 12, right?

Area new rectangle = 8 * 12 = 96

Area original rect. = 2 * 4 = 8

96 - 8 = 88 : OK?

Now go do yours...[you're lucky Ottawa Senators beat Buffalo earlier!]