(3a + 2)² - 36a² = (3a + 2)² - (6a)² = (3a+ 2 - 6a)(3a + 2 + 6a) =
= (2 - 3a)(9a + 2)
(3а + 2)² - 36а² =
= (3a + 2)² - (6a)² =
= ((3a + 2) - (6a))((3a + 2) + (6a)) =
= (3a + 2 - 6a)(3a + 2 + 6a) =
Решаем по формуле а² - b² = (a-b)(a+b)
(3a + 2)² - 36a² = (3a + 2)² - (6a)² = (3a+ 2 - 6a)(3a + 2 + 6a) =
= (2 - 3a)(9a + 2)
(3а + 2)² - 36а² =
= (3a + 2)² - (6a)² =
= ((3a + 2) - (6a))((3a + 2) + (6a)) =
= (3a + 2 - 6a)(3a + 2 + 6a) =
= (2 - 3a)(9a + 2)
Решаем по формуле а² - b² = (a-b)(a+b)