I guess the forum's having latex issues, so I'll try to write the model as best I can.

y_{t}= 50 + 0.8y_{t-1} + a_{t} - 0.2a_{t-1}

So, I've been pouring over notes trying to figure E[y_{t}] and VAR[y_{t}] but I just can't find it.

Can someone help me out please?