Step-by-step explanation:
To determine the rules, I'll give an example to enable us know the steps.
For example: 2a + b + c + 3b + a
First thing we will do is identify the terms that we consider as like terms:
Bring same letters together in a way tthey are next to each other:
2a + a + b + 3b + c
Then we combine the like terms together to get a simplified answer:
3a + 4b + c
The simplified answer = 3a + 4b + c
Hence, the rules for combining like terms​:
1) identify the terms that we consider as like terms
2) Bring same letters together in a way tthey are next to each other
3) combine the like terms together to get a simplified answer