Dolphin Depends: libstdc++6 (>= 4.9)

[Ashbringer]

Trying to install Dolphin on Mint 17.3 but when I try to install it I get "Depends: libstdc++6 (>= 4.9)". But the PPA's I installed are suppose to supply 4.9 or higher. What's wrong?

These are the terminal commands I used to try and install.

Code:

sudo add-apt-repository ppa:dolphin-emu/ppa
sudo add-apt-repository ppa:dolphin-emu/gcc-for-dolphin
sudo apt-get update
sudo apt-get install dolphin-emu