I am trying to find the modular inverse for $(n+1)\pmod {n^2}$ using EEA and I end up getting $1-n$ as the modular inverse. But, I want the inverse to be a positive number since its modular arithmetic.
Example: For $n = 3$, the modular inverse of $4 \pmod 9$ is $-2$ using EEA. But $7$ is positive modular inverse which I require.
I am not sure how to solve this problem. Can anyone help me ?
Thanks.
P.S: Sorry about the formatting. I am new to this website and still trying to get the hang of it.