How to solve this?

-n+4+21n=9

20n+4=9

20n=9-4

20n=5

N=5/20

N=1/4

The answer is 1/4

Step-by-step explanation:

move all terms with variables to one side and you get this : 20n=5

divide the variable side by 20 so you are left with the variable by itself. then do the same to the other side. 5/20 is 1/4