Instalar monodevelop 7.5 en ubuntu 18.04 ??
Abrimos la terminal y escribimos estos comandos para agregar los repositorios de monodevelop
sudo apt install apt-transport-https dirmngr
sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 3FA7E0328081BFF6A14DA29AA6A19B38D3D831EF
echo "deb https://download.mono-project.com/repo/ubuntu vs-bionic main" | sudo tee /etc/apt/sources.list.d/mono-official-vs.list
sudo apt update
Finalmente instalamos monodevelop
sudo apt-get install monodevelop