Answer :

n/5 -6 = 9 simplifies to n/5 = 15 then you can cross multiply and that comes out to 75 so n = 75
SchwarzschildRadius
So,

[tex] \frac{n}{5} + -6 = 9[/tex]
[tex] \frac{n}{5} - 6 = 9[/tex]

Add 6 to both sides
[tex] \frac{n}{5} = 15[/tex]

Multiply both sides by 5
[tex]n = 75[/tex]

Check
[tex] \frac{75}{5} - 6 = 9[/tex]
[tex]15 - 6 = 9[/tex]
[tex]9 = 9\ This\ checks.[/tex]

S = {75}