To begin our journey, lets start with an example of multiplying brackets together and see the pattern. Hopefully this will help us understand how to factorise a quadratic.
(x + 4)( x + 5)
I like to have a routine to follow so I always multiply my brackets out the same way.
- Multiply the first term in the first bracket by all the terms in the second bracket.
- Multiply the second term in the first bracket by all the terms in the second bracket.
- Add/subtract all these terms. Watch out for those minus signs!
- Continue until the last term in the first bracket.