1). 3a²b*(3 - 6a² - 4ab + 5ab²) = 3a²b*3 - 3a²b*6a² - 3a²b*4ab + 3a²b*5ab²
= 9a²b - 18a²⁺²b - 12a²⁺¹b¹⁺¹ + 15a²⁺¹b¹⁺² = 9a²b - 18a⁴b - 12a³b² + 15a³b³
2). (5 - 4a² + 3ab - 15ab²)*(-6ab)= -6ab*5 - 6ab(-4a²) - 6ab*3ab - 6ab*(-15ab²) =
= -30ab + 24a¹⁺²b - 18a¹⁺¹b¹⁺¹ + 90a¹⁺¹b¹⁺² = -30ab + 24a³b - 18a²b² + 90a²b³
3). (3ab - 5a²)*x = 10a³b² - 6a²b³
x = (10a³b² - 6a²b³):(3ab - 5a²)
x = 2ab²(5a² - 3ab):(3ab - 5a²)
x = -2ab²(3ab - 5a²):(3ab - 5a²)
x = -2ab²
4). 4(2x² - 5x + 4) - 2x(6 - 3x) = 8x² - 20x + 16 - 12x + 6x² =
= 14x² - 32x + 16