Respuesta :

naǫ
[tex]12m+12n=12(m+n)[/tex]

The answer is D.
[tex]12m+12n=12\times m+12\times n\\\\exclude\ common\ factor\ before\ parenthesis:\\\\\boxed{12m+12n=12(m+n)}\leftarrow answer\ \boxed{d.}[/tex]