Simple expressions can be factorised easily, however quadratics have to be factorised into two sets of brackets like this;
There’s a simple technique used to factorise a quadratic. We’ll use the following example:
The b and c terms of the quadratic expression should be simple to identify- in our example b=7 and c=12. The n terms that go in each bracket are factors of c that are also the sum of b. There are of course several factor pairs of 12:
- 1 and 12
- 2 and 6
- 3 and 4
- -1 and -12
- -2 and -6
- -3 and -4
All of these multiply to give c, but only 3 and 4 add together to give b, 7.
4 and 3 are our factors, so the quadratic factorises to:
