\(=\lim\limits_{x\rightarrow0}\left(x+2+\sqrt{3x+4}\right)\left[\frac{\frac{2x}{1+\sqrt{2x+1}}}{x^2+x}-\frac{sinx}{x^2+x}\right]\)
\(=\lim\limits_{x\rightarrow0}\left(x+2+\sqrt{3x+4}\right)\left[\frac{\frac{2}{1+\sqrt{2x+1}}}{x+1}-\frac{sinx}{x}.\frac{1}{\left(x+1\right)}\right]\)
\(=\left(2+\sqrt{4}\right)\left(\frac{1}{1}-\frac{1}{1}\right)=0\)