'

Select Category:

### Algebra Question 22r

22. Factorise the following quadratic expressions by completing the square.

r)

22. Factorise the following quadratic expressions by completing the square.

r)

r)

22. Factorise the following quadratic expressions by completing the square.

r)

Solution:

r)

Hence, the factors are       and

i.e.

Steps in Factorising Quadratic Expressions by Grouping.

1. Find two numbers which multiply to give ac and add to give b,

2. Replace b by these two numbers,

3. Group them together,

4. Factorise.

Factor Theorem: If when , then is a factor.