stephencheng 17.02.2009 15:55 $ x$ non-negative or $ L.H.S.$ is not integer. $ x \le 4$ or $ R.H.S.$ is negative., $ x=0,1,2$
gwen01 17.02.2009 16:41 Another approach $ \frac{2x+4}{4-x}=2^x>0$. So $ 2x+4$ and $ 4-x$ have the same signs and hence $ -2<x<4$. Checking $ x=-1,0,1,2,3$, it is easy to get the solutions $ x=0,1,2$.