Answer:
-2a + 20b - 2c
Step-by-step explanation:
(6a + 5b + 4c) + (–6c + 15b) + (–8a) = 6a + 5b + 4c - 6c + 15b - 8a
= 6a - 8a + 5b + 15b + 4c - 6c
= -2a + 20b - 2c
