Factorise algebraic expressions, including those involving indices, by determining common factors, eg factorise 3x to the power of 2 - 6x, 14ab + 12a to the power of 2, 21xy - 3x + 9x to the power of 2, 15p squared q cubed - 12pq to the power of 4

1. Al's Number Repairs - Remove common factors from an algebraic expression.
2. Al's Number Repairs - Factorise an algebraic expression.