Question

How do you factor the trinomial `2x^2+9x+9`?

Answer 1

`(2x+3)(x+3)`

Explanation:

`2x^2 +9x+9` is a quadratic trinomial which might have 2 binomial factors. Not all trinomials factorise.

Try to find factors of 2 and 9 which combine and ADD to make 9.

The signs will be the same, they are both positive.

`" "2" and " 9" "` find factors and cross multiply
`color(white)(...x)darrcolor(white)(..........)darr`
`" "2" and " 3 rarr 1xx3 = 3`
`" "1" and "3 rarr 2xx3 =ul6`
`color(white)(...........................................)9`

The factors are `(2x+3)(x+3)`