Using the remainder theorem, factorise each of the following completely :

2x³ + x² - 13x + 6

Using the remainder theorem, factorise each of the following completely :

3x³ + 2x² - 23x - 30

Using the remainder theorem, factorise each of the following completely :

x³ + x² - 4x - 4

Using the Remainder Theorem, factorise the expression 3x³ + 10x² + x - 6. Hence, solve the equation 3x³ + 10x² + x - 6 = 0.