$\frac{3}{5}$ . $\frac{6}{7}$ + $\frac{3}{7}$ : $\frac{5}{3}$ - $\frac{2}{7}$ : $\frac{5}{3}$
= $\frac{3}{5}$ . $\frac{6}{7}$ + $\frac{3}{7}$ . $\frac{3}{5}$ - $\frac{2}{7}$ . $\frac{3}{5}$
= $\frac{3}{5}$ . ($\frac{6}{7}$ + $\frac{3}{7}$ - $\frac{2}{7}$)
= $\frac{3}{5}$ . 1
= $\frac{3}{5}$
Chúc học tốt!!!