$ sudo apt-get update
$ sudo apt-get install libfreefem0 

libfreefem0 is installed in your system.

Make ensure the libfreefem0 package were installed using the commands given below,

$ sudo dpkg-query -l | grep libfreefem0 *

You will get with libfreefem0 package name, version, architecture and description in a table

libfreefem0 package basic information: