# What is a factor for this polynomial p(x) = 12x^4 + 13x^3 - 35x^2 - 16x +20 ?

A factor is $\left(x + 1\right)$
You can do this by trial and error starting at $x = \pm 1$
$p \left(1\right) = 12 + 13 - 35 - 16 + 20 = - 6$ so $\left(x - 1\right)$ is not a factor
$p \left(- 1\right) = 12 - 13 - 35 + 16 + 20 = 0$ so $\left(x + 1\right)$ is a factor