How do you factor 2x^2+9x+4?

1 Answer
Aug 8, 2015

(2x + 1) (x + 4)

Explanation:

The idea is to break down the middle term into two monomials which can be used in the factorisation process. Note that 2 * 4 = 8 = 8 * 1 , and that we may write 9 = 8 + 1 , which may help us in the process.

Let us write:
2x^2 + 9x + 4
= 2x^2 + 8x + x + 4
= 2x(x + 4) + (x + 4)
= (2x + 1) (x + 4)