Question 671864
Combine like terms to get 


8m^2 - 5mz + 4mz - m^2 + 4


8m^2 <font color="red">- 5mz + 4mz</font> - m^2 + 4


8m^2 <font color="red">-1mz</font> - m^2 + 4


8m^2 <font color="red">-mz</font> - m^2 + 4


8m^2-mz - m^2 + 4


8m^2 - m^2 -mz+ 4


<font color="red">8m^2 - m^2</font> -mz+ 4


<font color="red">8m^2 - 1m^2</font> -mz+ 4


<font color="red">7m^2</font> -mz+ 4


7m^2 -mz+ 4


So the answer is 7m^2 -mz+ 4