Show that the binomial is a factor of the polynomial. Then factor the polynomial completely. g(x)=x3−x2−20x; x+4
g(x)=

g(x) = x(x - 5)(x + 4)

Step-by-step explanation:

Here the binomial is x + 4, indicating that a root is -4.  Note that x is common to all terms of g(x)=x3−x2−20x, so we can immediately write g(x) in partially factored form as

g(x) = x(x^2 - x - 20).  Since -20 = -5*4,

g(x) = x(x - 5)(x + 4)