If you could specify where exactly you are facing the problem would be good. Anyhow assuming you are having problems with calculation part, I got the answer in the following way: X2 = 2 - [(-2)[(2-3)/(-2-3)]] X2 = 2 - [(-2)[-1/-5]] X2 = 2 - [-2/5] X2 = 2 + [2/5] X2 = 2.4 Hope this helps!