3(n-3)+6=5(n-9)

Solution for 3(n-3)+6=5(n-9) equation:

3(n-3)+6=5(n-9)

We simplify the equation to the form, which is simple to understand 
3(n-3)+6=5(n-9)

Reorder the terms in parentheses
+(+3n-9)+6=5*(n-9)

Remove unnecessary parentheses
+3n-9+6=+5+*(+n-9+)

Reorder the terms in parentheses
+3n-9+6=+(+5n-45)

Remove unnecessary parentheses
+3n-9+6=+5n-45

We move all terms containing n to the left and all other terms to the right. 
+3n-5n=-45+9-6

We simplify left and right side of the equation. 
-2n=-42

We divide both sides of the equation by -2 to get n. 
n=21