ГДЗ по математике 5 класс Мерзляк ФГОС Задание 1074

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\[1)\ \frac{7}{27}m \cdot \frac{9}{28}n = \frac{7 \cdot 9}{27 \cdot 28}mn =\]

\[= \frac{1}{3 \cdot 4}mn = \frac{1}{12}\text{mn}\]

\[2)\ 20x \cdot \frac{11}{35}y = \frac{20 \cdot 11}{35}xy =\]

\[= \frac{44}{7}xy = 6\frac{2}{7}\text{xy}\]

\[3)\ 3\frac{4}{15}x \cdot 1\frac{17}{28}y \cdot \frac{4}{7}z =\]

\[= \frac{49}{15} \cdot \frac{45}{28} \cdot \frac{4}{7}xyz = \frac{1 \cdot 3 \cdot 1}{1 \cdot 1 \cdot 1}xyz =\]

\[= 3xyz\]