5. 4 + 8a - 13 + 7a
Collect like terms:
4 - 13 + 8a + 7a
= -9 + 15a
6. 8n - 32 + 5m + 33- 3
Collect like terms:
8n + 5m - 32 + 33 - 3
= 8n + 5m - 2
7. 7 + 13a - 3 - 20 + 2a
Collect like terms:
7 - 3 - 20 + 13a + 2a
= -16 + 15a
8. -5 - 2c + 7 - 60
Collect like terms:
-5 + 7 - 60 - 2c
= -58 - 2c
