(а+б)³-4а²б-4аб² = (a + b)³ - 4ab(a + b) = (a + b)( (a+b)² - 4ab ) = (a + b)(a²+2ab+ + b² - 4ab) = (a + b)(a² - 2ab + b² ) = (a + b)(a - b)²
(а+б)³-4а²б-4аб² = (a + b)³ - 4ab(a + b) = (a + b)( (a+b)² - 4ab ) = (a + b)(a²+2ab+ + b² - 4ab) = (a + b)(a² - 2ab + b² ) = (a + b)(a - b)²