9-8n-23+21n+14-13n=

To simplify the expression \( 9 - 8n - 23 + 21n + 14 - 13n \), we can combine like terms.

1. Begin by combining the constant terms:

\[ 9 - 23 + 14 = 9 - 23 = -14 + 14 = 0 \]

2. Next, combine the terms with \( n \):

\[ -8n + 21n - 13n = (21 - 8 - 13)n = 0n = 0 \]

Putting it all together, we have:

\[ 0 + 0 = 0 \]

Thus, the simplified expression is:

\[ \boxed{0} \]