5a-8c+b+3c-9a+6b

Combining like terms, we have:

5a - 9a + 6b + b + 3c - 8c - 9
Simplifying further:
-4a + 7b - 5c - 9

To simplify the expression 5a-8c+b+3c-9a+6b, we can combine like terms.

The like terms are:

5a and -9a (both have the variable 'a')
-8c and 3c (both have the variable 'c')
b and 6b (both have the variable 'b')

Combining these like terms, we get:

(5a - 9a) + (-8c + 3c) + (b + 6b)

= -4a - 5c + 7b

Therefore, the simplified expression is -4a - 5c + 7b.

To simplify the expression 5a - 8c + b + 3c - 9a + 6b, we can combine like terms by combining the coefficients of the same variables.

First, let's combine the terms with the variable 'a':
5a - 9a = (5 - 9)a = -4a

Next, let's combine the terms with the variable 'c':
-8c + 3c = (-8 + 3)c = -5c

Now, let's combine the terms with the variable 'b':
b + 6b = (1 + 6)b = 7b

Putting it all together, the simplified expression is:
-4a - 5c + 7b