Упр.1059 ГДЗ Мерзляк Полонский 5 класс (Математика)

1) $$15 \frac{4}{9} — 4 \frac{4}{9} \cdot 3 \frac{3}{8}$$

$$15 \frac{4}{9} — 4 \frac{4}{9} \cdot 3 \frac{3}{8} = 15 \frac{4}{9} — \frac{40}{9} \cdot \frac{27}{8} = 15 \frac{4}{9} — 5 \cdot 3 = 15 \frac{4}{9} — 15 = \frac{4}{9}$$

2) $$\frac{81}{88}\cdot\left(6-1 \frac{13}{15}\cdot 1 \frac{19}{21}\right)$$

$$\frac{81}{88}\cdot\left(6-1 \frac{13}{15}\cdot 1 \frac{19}{21}\right) = \frac{81}{88}\cdot\left(6-\frac{28}{15}\cdot\frac{40}{21}\right) = \frac{81}{88}\cdot\left(6-\frac{8}{3}\right)$$
$$= \frac{81}{88}\cdot\frac{10}{3} = \frac{9}{4} = 2 \frac{1}{4}$$

3) $$\left(5 \frac{1}{16}-1 \frac{1}{8}\right)\left(\frac{5}{6}+\frac{3}{14}\right)$$

$$\left(5 \frac{1}{16}-1 \frac{1}{8}\right)\left(\frac{5}{6}+\frac{3}{14}\right) = \left(4 \frac{17}{16}-1 \frac{2}{16}\right)\left(\frac{35}{42}+\frac{9}{42}\right)$$
$$= 3 \frac{15}{16}\cdot\frac{44}{42} = \frac{63}{16}\cdot\frac{22}{21} = \frac{3\cdot 11}{8\cdot 1} = \frac{33}{8} = 4 \frac{1}{8}$$

4) $$5 \frac{1}{16}-1 \frac{1}{8}\cdot\left(\frac{5}{6}+\frac{3}{14}\right)$$

$$5 \frac{1}{16}-1 \frac{1}{8}\cdot\left(\frac{5}{6}+\frac{3}{14}\right) = 5 \frac{1}{16}-\frac{9}{8}\cdot\left(\frac{35}{42}+\frac{9}{42}\right)$$
$$= 5 \frac{1}{16}-\frac{9}{8}\cdot\frac{44}{42} = 5 \frac{1}{16}-\frac{9}{8}\cdot\frac{22}{21} = 5 \frac{1}{16}-\frac{3}{4}\cdot\frac{11}{7}$$
$$= 5 \frac{1}{16}-\frac{33}{28} = 5 \frac{1}{16}-1 \frac{5}{28} = 4 \frac{119}{112}-1 \frac{20}{112} = 3 \frac{99}{112}$$

Жители городов составляют $$73\%$$ всего населения России. Тогда сельское население составляет:

$$100\% — 73\% = 27\%$$

Ответ

1) $$\frac{4}{9}$$; 2) $$2 \frac{1}{4}$$; 3) $$4 \frac{1}{8}$$; 4) $$3 \frac{99}{112}$$; $$27\%$$.