That's actually a different question than http://www.wolframalpha.com/input/?i=x-3%2F+x-1%3D+x-4%2F+x-...

Bing's formatting of the results doesn't quite draw your eye to it - look for "Calculation" immediately below "All Results"

Are you outside the USA? I'm in Taiwan and Bing isn't calculating it for me either. It's just returning a bunch of normal search results in Chinese. Maybe calculation only works for queries coming from inside the USA.

Well, I'm in India and it does display the calculations for me.

I'm in Croatia and it's not returning calculations for me. It seems only select locations got this enabled in the first run...

That's weird, I didn't see it either this afternoon, but now I do.