How would you play this chord?

C/D, G#/F, etc. I don't know what this notation is asking me to do. I play piano. It's a Slash chord right? How do you finger these?

I believe you just play the C and the G#. The notes after the slash are bass notes. I often see D/F#. In that case I play the D chord while fretting the F# for a little extra bass.

.