(a-4)(a-3) (4a-1)(2-3a) (5m-2n)(3n-5m) (-2a-+4b) - вопрос №8258294434123523524 от steik20155 22.02.2020 22:21

Question

Математика: (a-4)(a-3) (4a-1)(2-3a) (5m-2n)(3n-5m) (-2a-+4b)

steik20155 · Answer

(a - 4)(a - 3) = а² - 3a - 4a + 12 = a² - 7a + 12
(4a - 1)(2 - 3a) = 8a - 12a² - 2 + 3a = -12a² + 11a - 2
(5m - 2n)(3n - 5m) = 15mn - 25m² - 6n² + 10mn = -25m² + 25mn - 6n²
(-2a - 3b)(-3a + 4b) = 6a² - 8ab + 9ab - 12b² = 6a² + ab - 12b²