2 примера тут.....
1) 2(b + 1) × (2b - 5) = (2b + 2) × (2b - 5) = 4b² - 10b + 4b - 10 = 4b² - 6b - 10
2) b(3b + 1) × (2b - 5) = (3b² + b) × (2b - 5) = 6b³ - 15b² + 2b² - 5b = 6b³ - 13b² - 5b
2 примера тут.....
1) 2(b + 1) × (2b - 5) = (2b + 2) × (2b - 5) = 4b² - 10b + 4b - 10 = 4b² - 6b - 10
2) b(3b + 1) × (2b - 5) = (3b² + b) × (2b - 5) = 6b³ - 15b² + 2b² - 5b = 6b³ - 13b² - 5b