Add 1x+1x+1\dfrac{1}{x} + \dfrac{1}{x+1}x1+x+11.
2x+1x(x+1)\dfrac{2x+1}{x(x+1)}x(x+1)2x+1
2x2+x\dfrac{2}{x^2+x}x2+x2
2x+1x+1\dfrac{2x+1}{x+1}x+12x+1
22x+1\dfrac{2}{2x+1}2x+12