For this case we must find the GCF of the following expression:
[tex]4x ^ 3-12x[/tex]
By definition we have that the GCF of an expression is given by the greatest common factor that divides both numbers without leaving remainder.
We find the factors of 4 and 12:
[tex]4: 1,2,4\\12: 1,2,3,4,6,12[/tex]
The GCF of both numbers is 4. Thus, the GCF of the expression is [tex]4x[/tex]:
[tex]4x (x ^ 2-3)[/tex]
Answer:
[tex]4x (x ^ 2-3)[/tex]