. (9x2 + 5) + (-2x2 - 8) + (x2 - 3)
9. 4a + (9a+3)
10. 7b + (4b - 6)
11. 8d2 + (6d2 - 4d)
12. (5x2 + 4) + (-3x2 - 4)
13. [-4x + (10 - 5x)] + 5x
14. 8 + [5 + (6 + x)]
15.
+3c - 7d
- 2c + 5d
- c + 8d
+4c - 6d
16.
3a + 8b - 5c
6a - 9b + 4c
-7a + b + 2c
17.
+6p - 3q + z
- 3p + 2q - z
- p + 00q___