Answer:
-7
Step-by-step explanation:
[tex] - 3(n + 4) = 9 \\ \\ - 3n - 12 = 9 \\ \\ - 3n = 12 + 9 \\ \\ - 3n = 21 \\ \\ n = \frac{ - 21}{3} \\ \\ n = - 7[/tex]
