Linuxmint and libstdc++6 ppa problem

[Bladeforce]

Hi,

I am trying to install dolphin on Linuxmint 17.3 KDe and after adding the dolphin emu ppa and the ppa that updates the gcc and libstdc++6 then issuing sudo apt-get update there is no updates for libstdc++6 to install?
All i am getting is this after issuing sudo apt-get upgrade

Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
The following packages have been kept back:
lib32stdc++6 libatomic1 libgfortran3 libgomp1 libitm1 libquadmath0
libstdc++6 libstdc++6:i386 libtsan0
0 to upgrade, 0 to newly install, 0 to remove and 9 not to upgrade.

Any help please?