Обчисли:
Розв'язок:
1) $1\frac{2}{13} \cdot 2\frac{3}{5} = \frac{15}{13} \cdot \frac{13}{5} =$
$= \frac{15 \cdot 13}{13 \cdot 5} = \frac{3 \cdot 1}{1 \cdot 1} = \frac{3}{1} = 3$;
2) $8\frac{2}{9} \cdot 1\frac{8}{37} = \frac{74}{9} \cdot \frac{45}{37} =$
$= \frac{74 \cdot 45}{9 \cdot 37} = \frac{2 \cdot 5}{1 \cdot 1} = \frac{10}{1} = 10$;
3) $\left(\frac{4}{7}\right)^2 = \frac{4^2}{7^2} = \frac{16}{49}$;
4) $1\frac{13}{15} \cdot \frac{5}{8} \cdot 2\frac{2}{7} =$
$= \frac{28 \cdot 5 \cdot 16}{15 \cdot 8 \cdot 7} = \frac{4 \cdot 1 \cdot 2}{3 \cdot 1 \cdot 1} =$
$= \frac{8}{3} = 2\frac{2}{3}$;
5) $3\frac{4}{5} \cdot 1\frac{37}{38} = \frac{19}{5} \cdot \frac{75}{38} =$
$= \frac{19 \cdot 75}{5 \cdot 38} = \frac{1 \cdot 15}{1 \cdot 2} =$
$= \frac{15}{2} = 7\frac{1}{2}$;
6) $11\frac{3}{8} \cdot 1\frac{11}{21} = \frac{91}{8} \cdot \frac{32}{21} =$
$= \frac{91 \cdot 32}{8 \cdot 21} = \frac{13 \cdot 4}{1 \cdot 3} =$
$= \frac{52}{3} = 17\frac{1}{3}$;
7) $\left(\frac{2}{5}\right)^3 = \frac{2^3}{5^3} = \frac{8}{125}$;
8) $1\frac{4}{13} \cdot 1\frac{5}{8} \cdot \frac{4}{17} =$
$= \frac{17 \cdot 13 \cdot 4}{13 \cdot 8 \cdot 17} = \frac{4}{8} = \frac{1}{2}$.