### Algebra: Factorisation

Note: This is a Flipped Classroom Lesson, i.e. students will be presented with the materials to learn on their own first. This includes short practices for them to check their understanding. We will focus on selected cases for discussion and to check understanding on what's presented when school re-opens.

In Sec 1, we learn FOUR methods to factorise algebraic expressions:

1. by Identifying the Highest Common Factor (HCF)
2. by Grouping
3. by Algebraic Identities (Special Products)
4. by "Cross Method"/ "Shoe-lace" Method

What you need to do:
• Watch the following video clips to learn the techniques.
• You may "break up" the series of video clips into smaller segments.
• The video may pause half-way to allow you attempt the question on your own before viewing how the expression could be factorised.
Keep in mind the following:
• What are the key things to look out for (in the given expression) for each method described?
• Is there any "pattern" in the expression that gives you an idea which method to use?
• When would you use each of this method? What are the deciding factors for your choice?

Method 1: By identifying the Highest Common Factor

Method 2: By Grouping

Method 3: By Special Products / Algebraic Identities

Method 4: Cross Method