Question

How its possible
\(\frac{n-1}{n+1} = 1 - \frac{2}{n+1}\)

Answer 1

Your goal is to get another n+1 in the numerator so that it cancels out.
\[\frac{n-1}{n+1}=\frac{n+1-2}{n+1}=\frac{n+1}{n+1}-\frac{2}{n+1}\]

Answer 2

hmm i think i get it, thank you :)