Упр.450 Часть 1 ГДЗ Виленкин Жохов 6 класс (Математика)

а) (5/12 + 3/8) * 12/19;
б) 6/7 * (11/18 — 5/12);
в) (3 1/14 — 2 5/7) * (7 — 6 3/5);
г) (3 1/12 — 2 3/4) * (1 1/6 — 5/12);
д) (6 7/12 — 5 11/15) * (1 3/17 — 10/17);
е) 2/3 * 9/16 — 5/24 * 2/5 — 1/6.

а) $$\left(\frac{5}{12}+\frac{3}{8}\right)\cdot\frac{12}{19}=\left(\frac{10}{24}+\frac{9}{24}\right)\cdot\frac{12}{19}=\frac{19}{24}\cdot\frac{12}{19}=\frac{1}{2}$$

б) $$\frac{6}{7}\cdot\left(\frac{11}{18}-\frac{5}{12}\right)=\frac{6}{7}\cdot\left(\frac{22}{36}-\frac{15}{36}\right)=\frac{6}{7}\cdot\frac{7}{36}=\frac{1}{6}$$

в) $$\left(3\frac{1}{14}-2\frac{5}{7}\right)\cdot\left(7-6\frac{3}{5}\right)=\left(3\frac{1}{14}-2\frac{10}{14}\right)\cdot\frac{2}{5}$$

$$=\left(2\frac{15}{14}-2\frac{10}{14}\right)\cdot\frac{2}{5}=\frac{5}{14}\cdot\frac{2}{5}=\frac{1}{7}$$

г) $$\left(3\frac{1}{12}-2\frac{3}{4}\right)\cdot\left(1\frac{1}{6}-\frac{5}{12}\right)=\left(3\frac{1}{12}-2\frac{9}{12}\right)\cdot\left(1\frac{2}{12}-\frac{5}{12}\right)$$

$$=\left(2\frac{13}{12}-2\frac{9}{12}\right)\cdot\left(\frac{14}{12}-\frac{5}{12}\right)=\frac{4}{12}\cdot\frac{9}{12}=\frac{1}{3}\cdot\frac{3}{4}=\frac{1}{4}$$

д) $$\left(6\frac{7}{12}-5\frac{11}{15}\right)\cdot\left(1\frac{3}{17}-\frac{10}{17}\right)=\left(6\frac{35}{60}-5\frac{44}{60}\right)\cdot\left(\frac{20}{17}-\frac{10}{17}\right)$$

$$=\left(5\frac{95}{60}-5\frac{44}{60}\right)\cdot\frac{10}{17}=\frac{51}{60}\cdot\frac{10}{17}=\frac{3}{6}\cdot\frac{1}{17}=\frac{1}{2}$$

е) $$\frac{2}{3}\cdot\frac{9}{16}-\frac{5}{24}\cdot\frac{2}{5}-\frac{1}{6}=\frac{18}{48}-\frac{10}{120}-\frac{1}{6}$$

$$=\frac{3}{8}-\frac{1}{12}-\frac{1}{6}=\frac{9}{24}-\frac{2}{24}-\frac{4}{24}=\frac{3}{24}=\frac{1}{8}$$

Ответ

а) $$\frac{1}{2}$$; б) $$\frac{1}{6}$$; в) $$\frac{1}{7}$$; г) $$\frac{1}{4}$$; д) $$\frac{1}{2}$$; е) $$\frac{1}{8}$$.