simplify 5a-8c +b+3c-9a+6b
To simplify `5a - 8c + b + 3c - 9a + 6b`, combine like terms:
Combine the `a` terms: 5a - 9a = -4a
Combine the `b` terms: b + 6b = 7b
Combine the `c` terms: -8c + 3c = -5c
Putting it all together, the simplified expression is `-4a + 7b - 5c`.