Hi and welcome to LQ!
The library libstdc++.so.5 usually is not installed by default. You should have the newer version libstdc++.so.6. Many distributions provide a package containing the old libstdc++.so.5 for compatibility reasons. Depending on your distribution (which is it?) you have to install the proper package. For example on Fedora the library libstdc++.so.5 is provided by the package
compat-libstdc++, whereas the newer version libstdc++.so.6 is provided by the package libstdc++.
Note: you can add the distribution you're using in your LQ profile, so it is displayed in the right column of your posts, under your nickname. This will let other users to know the distribution to which the problem is related and may help to give proper answers.