ГДЗ по алгебре 8 класс Макарычев ФГОС Задание 112

 

\[\boxed{\text{112\ (112).\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]

Пояснение.

Решение.

\[\textbf{а)}\frac{48x^{5}}{49y^{4}} \cdot \frac{7y^{2}}{16x^{3}} = \frac{48x^{5} \cdot 7y^{2}}{49y^{4} \cdot 16x^{3}} =\]

\[= \frac{16 \cdot 3 \cdot x^{5} \cdot 7 \cdot y^{2}}{7 \cdot 7 \cdot y^{4} \cdot 16{\cdot x}^{3}} = \frac{3x^{2}}{7y^{2}}\]

\[\textbf{б)}\frac{18m^{3}}{11n^{3}} \cdot \frac{22n^{4}}{9m^{2}} = \frac{18m^{3} \cdot 22n^{4}}{11n^{3} \cdot 9m^{2}} =\]

\[= 4mn\]

\[\textbf{в)}\frac{72x^{4}}{25y^{5}} \cdot \left( - \frac{2,5y^{4}}{27x^{5}} \right) =\]

\[= - \frac{72x^{4} \cdot 2,5y^{4}}{25y^{5} \cdot 27x^{5}} =\]

\[= - \frac{9 \cdot 8 \cdot x^{4} \cdot 25 \cdot 0,1 \cdot y^{4}}{25 \cdot y^{5} \cdot 3 \cdot 9 \cdot x^{5}} =\]

\[= - \frac{0,8}{3xy} = - \frac{8}{30xy} = - \frac{4}{15xy}\]

\[\textbf{г)} - \frac{35ax^{2}}{12b^{2}y} \cdot \frac{8ab}{21xy} =\]

\[= - \frac{35ax^{2} \cdot 8ab}{12b^{2}y \cdot 21xy} =\]

\[= - \frac{5 \cdot 7 \cdot a \cdot x^{2} \cdot 4 \cdot 2 \cdot ab}{3 \cdot 4 \cdot b^{2} \cdot y \cdot 7 \cdot 3 \cdot y} =\]

\[= - \frac{10xa^{2}}{9by^{2}}\]

\[\boxed{\text{112.\ }\text{еуроки}\text{-}\text{ответы}\text{\ }\text{на}\text{\ }\text{пятёрку}}\]

Пояснение.

Решение.

\[\textbf{а)}\ \frac{12}{5x} \cdot \frac{x^{3}}{12a} = \frac{12 \cdot x³}{5x \cdot 12a} = \frac{x^{2}}{5a}\]

\[\textbf{б)}\ \frac{8c^{2}}{15m} \cdot \frac{1}{4c^{2}} = \frac{8c^{2}}{15m \cdot 4c^{2}} =\]

\[= \frac{2}{15m}\]

\[\textbf{в)}\ \frac{11a^{4}}{6} \cdot \frac{12b}{a^{5}} = \frac{11a^{4} \cdot 12b}{6 \cdot a^{5}} =\]

\[= \frac{22b}{a}\]

\[\textbf{г)}\ \frac{{4n}^{2}}{3m^{2}} \cdot \frac{9m}{2} = \frac{4n^{2} \cdot 9m}{3m^{2} \cdot 2} = \frac{{6n}^{2}}{m}\]