(x³ + y²) x 10x² is equal to :

1. 10x⁵ + 10xy

2. 10x⁵ + 10x²y²

3. 10x⁵ - 10x²y²

4. -10x⁵ - 10x²y²

(a³ - b³) ÷ (a - b) is equal to :

1. a² + b² + ab

2. a² + b² - ab

3. a² - b² + ab

4. a² - b² - ab

Multiply :

$\dfrac{2}{3}$ ab by - $\dfrac{1}{4}$ a²b

Multiply :

-5cd² by - 5cd²