Решебник по алгебре 8 класс Макарычев ФГОС Задание 79

 

\[\boxed{\text{79\ (79).\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]

Пояснение.

Решение.

\[\textbf{а)}\ \frac{x - y^{\backslash z}}{\text{xy}} - \frac{x - z^{\backslash y}}{\text{xz}} =\]

\[= \frac{zx - zy - yx + yz}{\text{xyz}} =\]

\[= \frac{zx - yx}{\text{xyz}} = \frac{x \cdot (z - y)}{x\text{yz}} = \frac{z - y}{\text{yz}}\]

\[\textbf{б)}\ \frac{a - 2b^{\backslash a}}{3b} - \frac{b - 2a^{\backslash b}}{3a} =\]

\[= \frac{a^{2} - 2ab - b^{2} + 2ab}{3ab} =\]

\[= \frac{a^{2} - b^{2}}{3ab}\]

\[\textbf{в)}\ \frac{p - q^{\backslash q}}{p^{3}q^{2}} - \frac{p + q^{\backslash p}}{p^{2}q^{3}} =\]

\[= \frac{pq - q^{2} - p^{2} - pq}{p^{3}q^{3}} =\]

\[= \frac{- q^{2} - p^{2}}{p^{3}q^{3}} = - \frac{q^{2} + p^{2}}{p^{3}q^{3}}\]

\[\textbf{г)}\ \frac{3m - n^{\backslash 2n}}{3m^{2}n} - \frac{2n - m^{\backslash 3m}}{2mn^{2}} =\]

\[= \frac{6mn - 2n^{2} - 6mn + 3m^{2}}{6{m^{2}n}^{2}} =\]

\[= \frac{- 2n^{2} + 3m^{2}}{6{m^{2}n}^{2}}\]

\[\boxed{\text{79.\ }\text{еуроки}\text{-}\text{ответы}\text{\ }\text{на}\text{\ }\text{пятёрку}}\]

Пояснение.

Решение.

\[\textbf{а)}\frac{2xy - 1^{\backslash 3}}{4x^{3}} - \frac{3y - x^{\backslash 2x}}{6x^{2}} =\]

\[= \frac{6xy - 3 - 6xy + 2x^{2}}{12x^{3}} =\]

\[= \frac{2x^{2} - 3}{12x^{3}}\]

\[\textbf{б)}\ \frac{1 - {b^{2}}^{\backslash 2b}}{3ab} + \frac{2b^{3} - 1}{6ab^{2}} =\]

\[= \frac{2b - 2b^{3} + 2b^{3} - 1}{6ab^{2}} =\]

\[= \frac{2b - 1}{6ab^{2}}\]

\[\textbf{в)}\ \frac{1^{\backslash 5a^{2}}}{3a^{3}} - \frac{2^{\backslash 3}}{5a^{5}} =\]

\[\textbf{г)}\ \frac{{b^{2}}^{\backslash x}}{6x^{5}} - \frac{b^{\backslash 2}}{3x^{6}} =\]