i am not clear about combining like terms can you please help me understand?
When you see problems like you posted 3a+4b-3a-b, sometimes it is easier to see them separately.
For example: 3a+4b-3a-b
Can be viewed as:
and since there is no multiplication or division involved you can perform this in any order you want. So you could rewrite the equation like this: 3a-3a+4b-b.
3a-3a is 0 so now we can rewrite the equation like this: 4b-b. Then we just finish simplifying 4b-b= 3b.
I hope this helps, if yo have any questions let me know.