Question

If (x + 2) is a factor of x3 – 19x – p, find the value of p. Help please​

Answer 1

If $x-a$ is a factor of a polynomial $P(x)$ then, $a$ is its root.

So $-2$ is a root of $x^3-19x-p$

$(-2)^3-19\cdot(-2)-p=0\\-8+38-p=0\\p=30$