Câu hỏi 8
Tính giá trị $$\begin{aligned}&\left(\frac{2009}{2010}+\frac{2010}{2011}+\frac67\right)\left(\frac12+\frac{2009}{2010}+\frac{2010}{2011}+\frac25\right)\\[-1mm]&\quad-\left(\frac12+\frac{2009}{2010}+\frac{2010}{2011}+\frac67\right)\left(\frac{2009}{2010}+\frac{2010}{2011}+\frac25\right).\end{aligned}$$