The useful hint here is the shape of the area which is square. By definition, a square is a two-dimensional figure that consist of two parallel sides have the same equal measure. The only given dimension of a square is its side. The area is equal to the square of the side. Since the side has a measure of x²y³,
A = s² = (x²y³)²
By the laws of exponents, for this problem, just simply distribute the outer exponent to each of the inner exponent.
A = x⁴y⁶