For this case we have the following expression:
[tex]12c ^ 2 + cd-6d ^ 2[/tex]
Rewriting the expression we have:
[tex]12c ^ 2 + 9cd-8cd-6d ^ 2 =[/tex]
Grouping:
[tex](12c ^ 2 + 9cd) + (- 8cd-6d ^ 2) =[/tex]
We draw common factor from each group:
[tex]3c (4c + 3d) -2d (4c + 3d) =\\(3c-2d) (4c + 3d)[/tex]
Answer:
[tex](3c-2d)(4c+3d)[/tex]