Peppermint and Ubuntu are the same its mean that peppermint is based on ubuntu.

Here i post few tricks from various sites to improve and fix ubuntu or peppermint.

Trick number 1 update repositories we write in terminal :

sudo gedit /etc/apt/sources.list and
And write our password

then copy text from here and save :

Later write : sudo apt update

By editing sources.list at the end of document we can add own software

Simple info about system is writting command :neofetch