Respuesta :
Answer:
8m^4 -8m^3 -7m^2 -12 m
Step-by-step explanation:
(4m^4 - 8m^3 - 7m) + (4m^4 - 7m^2 - 5m)
I like to line them up vertically. I put 0 in the spots to keep them lined up
4m^4 - 8m^3 +0m^2 -7m
+4m^4 +0m^3 - 7m^2 - 5m
--------------------------------------------
8m^4 -8m^3 -7m^2 -12 m
[tex](4m^4-8m^3-7m)+(4m^4-7m^2-5m)\\\\=4m^4-8m^3-7m+4m^4-7m^2-5m\qquad\text{combine like terms}\\\\=(4m^4+4m^4)-8m^3-7m^2+(-7m-5m)\\\\=\boxed{8m^4-8m^3-7m^2-12m}[/tex]