1. a-(b+c)
2. 3a
3. 2m-(-p)+(-2q)=2m+p-12q
4. -abc
5. a-2b+c
6. ab+3bc-2ab-bc=ab-2ab+3bc-bc=2bc-ab=b(2c-a)
7. 2(2a-1)-3(a+1)+1 = 4a-2-3a-3+1 = a+4
8. a-(2b-(2a-2(b+a))) = a-(2b-(2a-2b-2a)) = a-(2b-2a+2b+2a) = a-2b+2a-2b-2a= a-4b
9. = 6abc
10.---------------
11. = -abc
12. 2a+3-1.5a+0.5 = 0.5a+3.5 = 0.5*(-3)+3.5 = -1.5+3.5 = 2