Упр.315 Часть 1 ГДЗ Дорофеев Петерсон 5 класс (Математика)

Выполни действия:

• 1) $$8\frac{3}{5}-\left(2\frac{4}{5}+1\frac{1}{5}\right)$$;
• 3) $$\left(2\frac{4}{7}+9\frac{6}{7}\right)-2\frac{6}{7}$$;
• 2) $$\left(3\frac{2}{9}+5\frac{8}{9}\right)-4\frac{1}{9}$$;
• 4) $$6\frac{1}{11}-\left(3\frac{4}{11}+1\frac{1}{11}\right)$$.

1) $$8 \frac{3}{5} — \left(2 \frac{4}{5} + 1 \frac{1}{5}\right) = 8 \frac{3}{5} — \left(3 + \frac{5}{5}\right) = 8 \frac{3}{5} — 4 = 4 \frac{3}{5}.$$

2) $$\left(3 \frac{2}{9} + 5 \frac{8}{9}\right) — 4 \frac{1}{9} = \left(8 + \frac{10}{9}\right) — 4 \frac{1}{9} = 9 \frac{1}{9} — 4 \frac{1}{9} = 5.$$

3) $$\left(2 \frac{4}{7} + 9 \frac{6}{7}\right) — 2 \frac{6}{7} = 2 \frac{4}{7} + \left(9 \frac{6}{7} — 2 \frac{6}{7}\right) = 2 \frac{4}{7} + 7 = 9 \frac{4}{7}.$$

4) $$6 \frac{1}{11} — \left(3 \frac{4}{11} + 1 \frac{1}{11}\right) = 6 \frac{1}{11} — 4 \frac{5}{11} = 1 \frac{7}{11}.$$

Ответ

1) $$4 \frac{3}{5}$$; 2) $$5$$; 3) $$9 \frac{4}{7}$$; 4) $$1 \frac{7}{11}$$.