tính lim[tex](\sqrt{9n^{2}+2n}-\sqrt{8n^{3}+6n+1}-n)[/tex]
lim[tex](\sqrt{9n^{2}+2n}-\sqrt{8n^{3}+6n+1}-n)[/tex][tex]\Leftrightarrow [tex]lim \sqrt{n^{3}}(\sqrt{\frac{9}{n}+\frac{2}{n^{2}}}-\sqrt{8+\frac{6}{n^{2}}+\frac{1}{n^{3}}}-\frac{1}{n^{2}})=-\infty[/tex] ...