Verified Answer :

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

So,

\(\frac{n}{5} + -6 = 9\)
\(\frac{n}{5} - 6 = 9\)

Add 6 to both sides
\(\frac{n}{5} = 15\)

Multiply both sides by 5
\(n = 75\)

Check
\(\frac{75}{5} - 6 = 9\)
\(15 - 6 = 9\)
\(9 = 9\ This\ checks.\)

S = {75}