Упр.762 ГДЗ Ткачёва 6 класс (Математика)

Выполнить действия:

1. $$\frac{\left(9\frac{1}{2}-11\right):(-0{,}003)}{\left(4{,}05-3\frac{13}{20}\right)\cdot20}$$
2. $$\frac{\left(-\frac{1}{5}:0{,}49\cdot\left(-1\frac{1}{6}\right)\right)}{\left(\frac{3}{4}\cdot1{,}8:\left(-1\frac{1}{5}\right):0{,}07\right)}$$
3. $$\frac{\left(\frac{2}{25}-1{,}008\right):\frac{4}{7}}{\left(3\frac{1}{4}-6\frac{5}{9}\right)\cdot2\frac{2}{17}}$$

1) Преобразуем выражение:

$$\frac{(9\frac{1}{2}-11):(-0{,}003)}{(4{,}05-3\frac{13}{20})\cdot 20}$$

$$9\frac{1}{2}-11=-1\frac{1}{2}=-1{,}5$$

$$-1{,}5:(-0{,}003)=500$$

$$4{,}05-3\frac{13}{20}=4{,}05-3{,}65=0{,}4$$

$$0{,}4\cdot 20=8$$

$$500:8=62{,}5$$

2) Вычислим:

$$\frac{(-\frac{1}{5}:0{,}49)\cdot(-1\frac{1}{6})}{\frac{3}{4}\cdot 1{,}8:(-1\frac{1}{5}):0{,}07}$$

$$-\frac{1}{5}:0{,}49=-\frac{1}{5}:\frac{49}{100}=-\frac{20}{49}$$

$$-\frac{20}{49}\cdot\left(-1\frac{1}{6}\right)=-\frac{20}{49}\cdot\left(-\frac{7}{6}\right)=\frac{10}{21}$$

$$\frac{3}{4}\cdot 1{,}8=\frac{3}{4}\cdot\frac{9}{5}=\frac{27}{20}$$

$$\frac{27}{20}:(-1\frac{1}{5})=\frac{27}{20}:\left(-\frac{6}{5}\right)=-\frac{9}{8}$$

$$-\frac{9}{8}:0{,}07=-\frac{9}{8}:\frac{7}{100}=-\frac{225}{14}$$

$$\frac{10}{21}:\left(-\frac{225}{14}\right)=-\frac{4}{135}$$

3) Найдём значение выражения:

$$\frac{( \frac{2}{25}-1{,}008):\frac{4}{7}}{(3\frac{1}{4}-6\frac{5}{9})\cdot 2\frac{2}{17}}$$

$$\frac{2}{25}-1{,}008=0{,}08-1{,}008=-0{,}928$$

$$-0{,}928:\frac{4}{7}=-0{,}928\cdot\frac{7}{4}=-1{,}624$$

$$3\frac{1}{4}-6\frac{5}{9}=3\frac{9}{36}-6\frac{20}{36}=-3\frac{11}{36}$$

$$-3\frac{11}{36}\cdot 2\frac{2}{17}=-\frac{119}{36}\cdot\frac{36}{17}=-7$$

$$-1{,}624:(-7)=0{,}232$$

Ответ

1) $$62{,}5$$; 2) $$-\frac{4}{135}$$; 3) $$0{,}232$$.