For MATLAB R2012a Student Edition, in Ubuntu 14.04, I had to install these prerequisites first:
sudo apt-get install default-jre libxtst6:i386 libXext6:i386 libxi6:i386 libncurses5:i386 libxt6:i386 libxpm4:i386 libxmu6:i386 libxp6:i386
Next I installed/activated per MATLAB's instructions (sudo ./install). I answered "yes" when the installer asked to add a symbolic link in /usr/local/bin/
Finally, when launching MATLAB, I have to specify that it run in 32-bit mode:
matlab -glnx86
I assembled those steps from this answer: https://askubuntu.com/questions/363878/how-to-install-32-bit-matlab-in-ubuntu-64-bit
and the Ubuntu MATLAB guide:
https://help.ubuntu.com/community/MATLAB
Optional
I didn't want to type the -glnx86 option each time I launch MATLAB, so I replaced the matlab symbolic link in /usr/local/bin/ with a script that automatically specifies the -glnx86 option:
ls -l /usr/local/bin/matlab #note the destination of the symbolic link
sudo mv /usr/local/bin/matlab /usr/local/bin/matlab.bak
#ensure the first path below matches your symbolic link's destination
echo '/usr/local/MATLAB/R2012a_Student/bin/matlab -glnx86 "$@"' | sudo tee /usr/local/bin/matlab
sudo chmod +x /usr/local/bin/matlab
With that, I can type 'matlab' and it launches properly. (The "$@" in the script forwards all input arguments to matlab.) There's probably a more elegant way to accomplish this, but it worked.
I also encountered a "/lib/libc.so.6: not found" error on matlab startup, which I fixed by following this answer.