10. What is (ab) + (3a)?
A. 3a + b B. 3a2 + b
C. 3a + ab
D. 4ab
11. What is (a + 1)-(2a - 1)?
A. -a + 2 B. a2 + 2
С. За
D. 3a2
12. What is (5a - b) - (3a - b)?
A. 8ab-2ab B. &a2 - 2b2
C. 2a
D. 2ab
13. What is (a - b+ 2) - (a - b + c)?
A. 3ab-bc + 2 B. 3a2-b2 c2_2 C. 2a - 2b+c+2 D. c + 2
14. What is (b) - (3a) - (4c)? EST
A. 12abc B. 3ab-4c2
C. a-b-C D. 3a - b - 40
15. What is (ab) - (3a)?
A. 3a - b B. 3a2 - b C. 3a - ab D. 4ab​