Respuesta :
17m - 12n - 1 + 4 - 13m - 12
Bring like terms together :-
= 17m - 13m - 12n - 1 + 4 - 12
= 4m - 12n - 9
Bring like terms together :-
= 17m - 13m - 12n - 1 + 4 - 12
= 4m - 12n - 9