GCSE Secondary Maths Age 13-17 - Algebra: Factorisation - Explained

The video tutorial explains how to fully factorize the expression 20X^2 - 5. It begins by identifying a common factor of 5, which is factored out. The remaining expression inside the bracket is recognized as a difference of two squares, which is further factorized. The tutorial emphasizes the importance of reading questions carefully to ensure full factorization, as partial factorization only earns partial marks. The video also highlights the significance of understanding the difference of two squares to gain extra marks.

What is the first step in factorizing the expression 20X^2 - 5?

• Identify the difference of two squares

• Extract the common factor of 5

• Multiply by 4

• Add 5 to both terms

After extracting the common factor, what type of expression is left inside the bracket?

• A linear equation

• A quadratic trinomial

• A sum of cubes

• A difference of two squares

What is the square root of 4X^2 in the expression?

• 4X

• 2X

• X

• 2

Why is it important to fully factorize an expression?

• All of the above

• To simplify calculations

• To gain extra marks

• To make it easier to solve equations

How many marks are awarded for fully factorizing the expression?

• One mark

• Two marks

• Three marks

• Four marks