Factoring the square of 4-12 (X-Y) + 9 (X-Y)

Factoring the square of 4-12 (X-Y) + 9 (X-Y)

4-12(x-y)+9(x-y)²
=[2-3﹙x-y﹚]²
=﹙2-3x+3y﹚²