Answer:
[tex]3c(3(b+1)a+4b)[/tex]
Step-by-step explanation:
The given equation is:
[tex]9abc+3ac+12bc[/tex]
Taking 3c common from all the above terms, we get
ā[tex]3c(3ab+a+4b)[/tex]
ā[tex]3c(3(b+1)a+4b)[/tex]
which is the required factorised form.
