rồi, h thì dễ hỉu @@
\(\left(\frac{74}{7}+\frac{19}{5}\right)-\left(\frac{39}{7}-\frac{6}{5}\right)=\frac{74}{7}+\frac{19}{5}-\frac{39}{7}+\frac{6}{5}=\left(\frac{74}{7}-\frac{39}{7}\right)+\left(\frac{19}{5}+\frac{6}{5}\right)=\frac{35}{7}+\frac{25}{5}=5+5=10\)