50/50 means you get 50% in Steem power and 50% in SBD.
So, if your post is 1$ you get 75% of that amount divided 50/50 between both tokens.
75% is the current proportion on which you are rewarded, 25% is for people who upvote you, more or less.
Those 22$ are actually 22SBD that you can power up or withdraw to exchanges for trading.

If you want to power up them you should exchange first your SBD for Steem at the internal market, very easy.
I recommend you to power up them so your vote power will increase.
If you power down your Steem power you unstake and your voting power decrease.
SBD and Steem are both tradable in many exchanges.

Posted using Partiko iOS