node & nodejs have different version

I successfully update/install the latest version of node js by using those commands (the official curl way not working for me) :

sudo npm cache clean -f
sudo npm install -g n
sudo n stable

sudo ln -sf /usr/local/n/versions/node//bin/node /usr/bin/node

However, the version of my node and nodejs become different :

$ node --version
v5.0.0
$ nodejs --version
v0.10.25

It seems the new node is installed in /usr/local/bin/node, so i tried :

sudo ln -s /usr/bin/nodejs /usr/local/bin/node

But it returns :

ln: failed to create symbolic link ‘/usr/local/bin/node’: File exists

I also use this link :

$ sudo ln -s /usr/bin/nodejs /usr/bin/node
ln: failed to create symbolic link ‘/usr/bin/node’: File exists

I will use some frameworks that depend on node, like Ionic. Which node version will it use?

What should i do to solve this?

Thanks a lot for your help