Упр.15.13 ГДЗ Рабочая тетрадь Зубарева Мордкович 6 класс Экзамен (Математика)

а) 18:10 7/20; 4 1/2 :2/3; 5 17/24 :2/3;
б) 17 5/14 :2 2/27; 39:9 3/5; 7/12 :3 1/16;
в) 63 1/3 :5 2/11; 6 1/8 :3 1/2; 5 9/11 :13 5/7;
г) 32:9 3/5; 25 5/7 :1 1/35; 21 7/9 :4 2/3.

При делении на дробь умножаем на обратную дробь:

$$a:b=a\cdot \frac{1}{b}$$

а)

$$18:10\frac{7}{20}=18:\frac{207}{20}=18\cdot \frac{20}{207}=\frac{40}{23}=1\frac{17}{23}$$
$$4\frac{1}{2}: \frac{2}{3}=\frac{9}{2}\cdot \frac{3}{2}=\frac{27}{4}=6\frac{3}{4}$$
$$5\frac{17}{24}:\frac{2}{3}=\frac{137}{24}\cdot \frac{3}{2}=\frac{137}{16}=8\frac{9}{16}$$

б)

$$17\frac{5}{14}:2\frac{2}{27}=\frac{243}{14}:\frac{56}{27}=\frac{243}{14}\cdot \frac{27}{56}=\frac{6561}{784}=8\frac{289}{784}$$
$$39:9\frac{3}{5}=39:\frac{48}{5}=39\cdot \frac{5}{48}=\frac{65}{16}=4\frac{1}{16}$$
$$\frac{7}{12}:3\frac{1}{16}=\frac{7}{12}:\frac{49}{16}=\frac{7}{12}\cdot \frac{16}{49}=\frac{4}{21}$$

в)

$$63\frac{1}{3}:5\frac{2}{11}=\frac{190}{3}:\frac{57}{11}=\frac{190}{3}\cdot \frac{11}{57}=\frac{110}{9}=12\frac{2}{9}$$
$$6\frac{1}{8}:3\frac{1}{2}=\frac{49}{8}:\frac{7}{2}=\frac{49}{8}\cdot \frac{2}{7}=\frac{7}{4}=1\frac{3}{4}$$
$$5\frac{9}{11}:13\frac{5}{7}=\frac{64}{11}:\frac{96}{7}=\frac{64}{11}\cdot \frac{7}{96}=\frac{14}{33}$$

г)

$$32:9\frac{3}{5}=32:\frac{48}{5}=32\cdot \frac{5}{48}=\frac{10}{3}=3\frac{1}{3}$$
$$25\frac{5}{7}:1\frac{1}{35}=\frac{180}{7}:\frac{36}{35}=\frac{180}{7}\cdot \frac{35}{36}=25$$
$$21\frac{7}{9}:4\frac{2}{3}=\frac{196}{9}:\frac{14}{3}=\frac{196}{9}\cdot \frac{3}{14}=\frac{14}{3}=4\frac{2}{3}$$

Ответ

а) $$1\frac{17}{23};\ 6\frac{3}{4};\ 8\frac{9}{16}$$
б) $$8\frac{289}{784};\ 4\frac{1}{16};\ \frac{4}{21}$$
в) $$12\frac{2}{9};\ 1\frac{3}{4};\ \frac{14}{33}$$
г) $$3\frac{1}{3};\ 25;\ 4\frac{2}{3}$$