[ Answer ]
[tex]\boxed{N \ = \ 2}[/tex]
[ Explanation ]
-3(n + 5) = -21
Divide Both Sides By -3
[tex]\frac{-3(n \ + \ 5)}{-3}[/tex] = [tex]\frac{-21}{3}[/tex]
Simplify:
N + 5 = 7
Subtract 5 From Both Sides:
N + 5 - 5 = 7 - 5
Simplify:
N = 2
[tex]\boxed{[ \ Eclipsed \ ]}[/tex]