Question

How do you factor `4n^2-20n+24`?

Answer 1

`4(n-2)(n-3)`

Explanation:

The first step is to take out the `color(blue)"common factor"` of 4, from each term.

`rArr4n^2-20n+24=4(n^2-5n+6)`

To factorise the quadratic expression in the bracket.

Consider the factors of 6 which also sum to -5.

These are - 3 and - 2.

since `-3xx-2=+6" and " -3+(-2)=-5`

`rArrn^2-5n+6=(n-2)(n-3)`

`rArr4n^2-20n+24=4(n-2)(n-3)`