2(a+bc)=2a+2bc
3.(ab-cb-ba+bc)= 3ab-3cb-3ba+3bc
Since the brackets and multiplication have a higher order than the rest.
Cb=Bc
Ab=ba
Ac=Ca
Because multiplication is commutative.
2a+2bc + cb +ab + ac -(3ab-3cb-3ba+3bc)
2a + 2bc + cb + ab + ac(+ -3ab - - 3cb - -3ba +-3bc)
2a + 2bc + cb + ab + ac -3ab + 3cb + 3ba -3bc
2a + (2bc-3bc +cb + 3cb ) + (ab -3ab + 3ba) + ac
=2a + 3cb + ba+ ac OR 2a +3bc + ab + ac
The Or is just a different way to write it.
Hope this helps