Answer
In set-builder notation, the solutions are given by ${n | n \gt -3 }$.
Work Step by Step
Write: $9 - 4n \gt 21$
Subtract 9 from each side.
$9 - 9 - 4n \gt 21 -9 $
Simplify:
$ - 4n \gt 12$
Divide each side by 4:
$-n \gt 3$
Then $n \gt -3$.
In set-builder notation, the solutions are given by $\{n | n \gt -3 \}$.
