1)(а-b)³-3(a-b)²=(a-b)(a-b)²-3(a-b)²=(a-b-3)(a-b)²
2)(x + y)³+2x(x + y)² =(x + y)²*(x + y)+2x(x + y)² = (x + y)² (3x + y)
3)(m + n)³-m²-2mn-n² =(m + n)³-(m+n)²=(m+n)² *(m+n)-(m+n)²=(m+n)² (m+n -1)
4) x² - 4xy + 4y² - (x - 2y)² = (x - 2y)² - (x - 2y)² = 0