Answer :
[tex]6x^3-9x^2-12x\\
first\ finding\ the\ GCF\ of\ all\ terms:\\\\
6: \ 1,2,3,6\\
9: \ 1,3,9\\
12: \ 1,3,4,6,12\\
GCF=3x\\
3x(\ \ \ )\\\\
Next\ divide\ each\ term\ of\ the\ original\
expression\ 6x^3-9x^2-12x\\
by\ GCF:\\\\
-6x^3:3x=-2x^2\\
-9x^2:3x=-3x\\
-12x:3x=-4\\\\
Answer:
3x(-2x^2-3x-4)[/tex]