\(Đặt\)
\(A=\frac{\frac{1}{2}+\frac{1}{3}+\frac{1}{2013}}{2012+\frac{2012}{2}+\frac{2011}{3}+......+\frac{1}{2013}}\)
\(A=\frac{\left(\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+.....+\frac{1}{2013}\right)}{\left(\frac{2012}{2}+1\right)+\left(\frac{2011}{3}+1\right)+......+\left(\frac{1}{2013}+1\right)}\)
\(A=\frac{\left(\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+.....+\frac{1}{2013}\right)}{\frac{2014}{2}+\frac{2014}{3}+\frac{2014}{4}+....+\frac{2014}{2013}}\)
\(A=\frac{\left(\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+.....+\frac{1}{2013}\right)}{2014.\left(\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+....+\frac{1}{2013}\right)}=\frac{1}{2014}\)
ai trả lời dùm mình k nhiệt tình cho
ai trả lời dùm mình k nhiệt tình cho