Answer:
8. 11v
9. -19x
10. 6p
11. 16n
12. -4n - 5
13. 15r
14. 9n + 1
Explanation:
8. -v + 12v = 11v
9. -8x - 11x = -19x
10. 4p + 2p = 6p
11. 5n + 11n = 16n
12. n + 4 - 9 - 5n = n - 5n + 4 - 9 = -4n - 5
13. 12r + 5 + 3r - 5 = 12r + 3r + 5 - 5 = 15r
14. -5 + 9n + 6 = 9n + 1