Задание 241 Вариант 2 Самостоятельная работа ГДЗ Дидактические материалы Чесноков 6 класс (Математика)

а)

$$(-5{,}8+3{,}6)\cdot(-1{,}2)-3{,}04$$
$$-5{,}8+3{,}6=-2{,}2$$
$$-2{,}2\cdot(-1{,}2)=2{,}64$$
$$2{,}64-3{,}04=-0{,}4$$

$$(-5{,}8+3{,}6)\cdot(-1{,}2)-3{,}04=-0{,}4$$

б)

$$-6{,}03\cdot2{,}1-(-0{,}14)\cdot(-0{,}05)$$
$$-6{,}03\cdot2{,}1=-12{,}663$$
$$(-0{,}14)\cdot(-0{,}05)=0{,}007$$
$$-12{,}663-0{,}007=-12{,}67$$

$$-6{,}03\cdot2{,}1-(-0{,}14)\cdot(-0{,}05)=-12{,}67$$

в)

$$\frac{17}{18}\cdot\left(-1\frac{4}{7}\right)-\frac{4}{21}\cdot\left(-1\frac{1}{6}\right)$$
$$-1\frac{4}{7}=-\frac{11}{7},\qquad -1\frac{1}{6}=-\frac{7}{6}$$
$$\frac{17}{18}\cdot\left(-\frac{11}{7}\right)=-\frac{187}{126}$$
$$\frac{4}{21}\cdot\left(-\frac{7}{6}\right)=-\frac{2}{9}$$
$$-\frac{187}{126}-\left(-\frac{2}{9}\right)=-\frac{187}{126}+\frac{28}{126}=-\frac{159}{126}=-\frac{53}{42}=-1\frac{11}{42}$$

$$\frac{17}{18}\cdot\left(-1\frac{4}{7}\right)-\frac{4}{21}\cdot\left(-1\frac{1}{6}\right)=-1\frac{11}{42}$$

г)

$$\left(-1\frac{7}{8}\cdot1\frac{4}{5}+2\frac{9}{16}\right)\cdot3\cdot\left(-\frac{8}{9}\right)$$
$$-1\frac{7}{8}=-\frac{15}{8},\qquad 1\frac{4}{5}=\frac{9}{5},\qquad 2\frac{9}{16}=\frac{41}{16}$$
$$-\frac{15}{8}\cdot\frac{9}{5}=-\frac{27}{8}$$
$$-\frac{27}{8}+\frac{41}{16}=-\frac{54}{16}+\frac{41}{16}=-\frac{13}{16}$$
$$-\frac{13}{16}\cdot3\cdot\left(-\frac{8}{9}\right)=\frac{13}{16}\cdot\frac{24}{9}=\frac{13}{6}=2\frac{1}{6}$$

$$\left(-1\frac{7}{8}\cdot1\frac{4}{5}+2\frac{9}{16}\right)\cdot3\cdot\left(-\frac{8}{9}\right)=2\frac{1}{6}$$