1) $$\frac{5}{6} m \cdot \frac{7}{10} n = \frac{5 \cdot 7}{6 \cdot 10} mn = \frac{1 \cdot 7}{6 \cdot 2} mn = \frac{7}{12} mn$$
2) $$\frac{7}{3} a \cdot 3\frac{1}{3} b = \frac{7}{3} a \cdot \frac{10}{3} b = \frac{7 \cdot 10}{3 \cdot 3} ab = \frac{70}{9} ab = 7\frac{7}{9} ab$$
Ответ: 1) $$\frac{7}{12} mn$$; 2) $$7\frac{7}{9} ab$$