First error:
The following packages have unmet dependencies:

virtualbox-qt: Depends: libgcc1 (>= 1:4.1.1) but 1:4.9.1-0ubuntu1 is to be installed
               Depends: libqt4-network (>= 4:4.5.3) but 4:4.8.5+git192-g085f851+dfsg-2ubuntu4.1 is to be installed
               Depends: libqt4-opengl (>= 4:4.7.2) but 4:4.8.5+git192-g085f851+dfsg-2ubuntu4.1 is to be installed
               Depends: libqtcore4 (>= 4:4.8.0) but 4:4.8.5+git192-g085f851+dfsg-2ubuntu4.1 is to be installed
               Depends: libqtgui4 (>= 4:4.8.0) but 4:4.8.5+git192-g085f851+dfsg-2ubuntu4.1 is to be installed
               Depends: libstdc++6 (>= 4.6) but 4.8.4-2ubuntu1~14.04 is to be installed
               Depends: virtualbox (= 4.3.10-dfsg-1ubuntu5) but 4.3.10-dfsg-1ubuntu5 is to be install