Re: HSC 2013 4U Marathon
\frac{x+1-1}{x+1} + \frac{x^2+1-1}{(1+x)(1+x^2)} + \frac{x^4+1-1}{(1+x)(1+x^2)(1+x^4)} + \dots
= 1 - \frac{1}{x+1} + \frac{1}{x+1} - \frac{1}{(1+x)(1+x^2)} + \frac{1}{(1+x)(1+x^2)} - \frac{1}{(1+x)(1+x^2)(1+x^4)} \dots
= 1
I hope that's right and you can...