How do you factor $5n^2-22n+8$ ?

Question

1357 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-07-01T16:19:02

$5n^2-22n+8 =(5n-2)(n-4)$

Use an AC method:

Find a pair of factors of $AC = 5*8=40$ with sum $B=22$

The pair $20,2$ works.

Use that pair to split the middle term and factor by grouping:

$5n^2-22n+8 = (5n^2-20n)-(2n-8)$

$=5n(n-4)-2(n-4)$

$=(5n-2)(n-4)$

How do you factor 5n^2-22n+85n^2-22n+8?