Both (m + n)2<span> and 36 are </span>perfect<span> squares, and 12(m + n) is twice the product of (m + n) and 6. Since the middle term is positive, the pattern is (a + b)</span>2<span> = a</span>2<span> + 2ab + b</span>2. Place the x2<span> tile, 4 x-tiles and 4 1-tiles in the grid. Fill the outside sections of the grid with x-tiles and 1-tiles that complete the pattern.</span>