If we assume that the length of the sides of the square are x, then the resulting area will then be:
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Then we have the rectangle, whose length triples the square. This will be represented by: 3x
And the width of this rectangle is 2 units less than the side of the square, so it is represented as: (x - 2)
The area of the rectangle can then be represented by:

The questions says that the two areas are equal, so set the areas equal to each other, and you get:
or C