Сократите дробь:
a) \(\frac{x^{2}-2}{x+\sqrt{2}}\);
б) \(\frac{\sqrt{5}-a}{5-a^{2}}\);
в) \(\frac{\sqrt{x}-5}{25-x}\);
г) \(\frac{\sqrt{2}+2}{\sqrt{2}}\);
д) \(\frac{5+\sqrt{10}}{\sqrt{10}}\);
e) \(\frac{2 \sqrt{3}-3}{5 \sqrt{3}}\).
\(\frac{x^2-2}{x+\sqrt{2}}=\frac{(x-\sqrt{2})(x+\sqrt{2})}{x+\sqrt{2}}=x-\sqrt{2}\).
\(\frac{\sqrt{5}-a}{5-a^2}=\frac{\sqrt{5}-a}{(\sqrt{5}-a)(\sqrt{5}+a)}=\frac{1}{\sqrt{5}+a}\).
\(\frac{\sqrt{x}-5}{25-x}=-\frac{\sqrt{x}-5}{x-25}=-\frac{\sqrt{x}-5}{(\sqrt{x}-5)(\sqrt{x}+5)}=-\frac{1}{\sqrt{x}+5}\).
\(\frac{\sqrt{2}+2}{\sqrt{2}}=\frac{\sqrt{2}(1+\sqrt{2})}{\sqrt{2}}=1+\sqrt{2}\).
\(\frac{5+\sqrt{10}}{\sqrt{10}}=\frac{\sqrt{5} \cdot \sqrt{5}+\sqrt{5} \cdot \sqrt{2}}{\sqrt{5} \cdot \sqrt{2}}=\frac{\sqrt{5}(\sqrt{5}+\sqrt{2})}{\sqrt{5} \cdot \sqrt{2}}=\frac{\sqrt{5}+\sqrt{2}}{\sqrt{2}}\).
\(\frac{2 \sqrt{3}-3}{5 \sqrt{3}}=\frac{2 \sqrt{3}-\sqrt{3} \cdot \sqrt{3}}{5 \sqrt{3}}=\frac{\sqrt{3}(2-\sqrt{3})}{5 \sqrt{3}}=\frac{2-\sqrt{3}}{5}\).
Решебник
"Алгебра - Учебник" по предмету Алгебра за 8 класс.
Aвторы:
Макарычев Ю.Н., Миндюк Н.Г., Нешков К.И., Суворова С.Б.
Задание
Сократите дробь: a) \(\frac{x^{2}-2}{x+\sqrt{2}}\); б) \(\frac{\sqrt{5}-a}{5-a^{2}}\); в) \(\frac{\sqrt{x}-5}{25-x}\); г) \(\frac{\sqrt{2}+2}{\sqrt{2}}\); д) \(\frac{5+\sqrt{10}}{\sqrt{10}}\); e) \(\frac{2 \sqrt{3}-3}{5 \sqrt{3}}\).