"and" indicates the operation addition (+)
(3xyz + 4yz + 5zx) + (7xz - 6yz + 4xyz) + (-9xyz - 11zy + 9xz)
Find like terms on the parenthesis, then add. In this case there are no like terms in the parentheses.
Add like terms.
The like terms are:
= 3xyz + 4xyz - 9xyz,
= 4yz - 6yz -11zy, and
= 5zx + 7xz + 9xz
Add the like terms:
= (3 + 4 - 9)xyz
= (7 - 9)xyz
= -2xyz
= (4 - 6 - 11)yz
= (-2 - 11)yz
= -13yz
= (5 + 7 + 9)xz
= (12 + 9) xz
= 21xz
The final answer is:
-2xyz - 13yz + 21xz
(In some cases, you can switch the terms by each other, but the answer is considered no matter what the arrangement of the terms should be)
