Объяснение:
1) 2a(a - b) + 3b(a-b) = 2a² - 2ab + 3ab - 3b² = 2a² -3b² - ab
2) 3n(m - 3) + 5m (m-3) = 3nm - 9n + 5m ² - 15m = 5m² + 3nm - 9n - 15m
3) 5a (x + y) - 4b (x + y) = 5ax + 5ay - 4bx - 4by
4) 7a(c-d)-2b(c-d) = 7ac - 7ad - 2bc + 2bd
Объяснение:
1) 2a(a - b) + 3b(a-b) = 2a² - 2ab + 3ab - 3b² = 2a² -3b² - ab
2) 3n(m - 3) + 5m (m-3) = 3nm - 9n + 5m ² - 15m = 5m² + 3nm - 9n - 15m
3) 5a (x + y) - 4b (x + y) = 5ax + 5ay - 4bx - 4by
4) 7a(c-d)-2b(c-d) = 7ac - 7ad - 2bc + 2bd