\[\boxed{\text{94\ (94).\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
Пояснение.
Решение.
\[= \frac{2a \cdot (a - b) \cdot (a + b)}{a \cdot (a - b) \cdot (a + b)} = 2\]
\[\textbf{г)}\ \frac{x^{2} - 4}{5x - 10} - \frac{x^{2} + 4x + 4}{5x + 10} =\]
\[= \frac{x + 2}{5} - \frac{x + 2}{5} = 0\]
\[\boxed{\text{94.\ }\text{еуроки}\text{-}\text{ответы}\text{\ }\text{на}\text{\ }\text{пятёрку}}\]
Пояснение.
Решение.
\[\textbf{а)}\ \frac{c^{\backslash b + c}}{b - c} + \frac{b^{2} - 3bc}{b^{2} - c^{2}} =\]
\[= \frac{cb + c^{2} + b^{2} - 3bc}{b^{2} - c^{2}} =\]
\[= \frac{c^{2} + b^{2} - 2bc}{b^{2} - c^{2}} =\]
\[\textbf{б)}\ \frac{a + 3}{a^{2} - 1} - \frac{1}{a^{2} + a} =\]
\[= \frac{a + 3^{\backslash a}}{(a - 1) \cdot (a + 1)} - \frac{1^{\backslash a - 1}}{a \cdot (a + 1)} =\]
\[= \ \frac{a^{2} + 3a - a + 1}{a \cdot (a + 1) \cdot (a - 1)} =\]
\[= \frac{a^{2} + 2a + 1}{a \cdot (a + 1) \cdot (a - 1)} =\]
\[= \frac{a + 1}{a \cdot (a - 1)}\]