Question

ДАЮ 20 БАЛОВ ЗА ПРИМЕР!!

Answer 1

$\Large \it \frac{1}{ \sqrt{10} - 2 } - \frac{1}{ \sqrt{10} + 2 } \Rightarrow \\ \large \it \Rightarrow \: \underbrace{\frac{1}{ \sqrt{10} - 2 }} _{ \large\sqrt{10} + 2} - \underbrace{\frac{1}{ \sqrt{10} + 2 }} _{ \large \: \sqrt{10} - 2 } = \\\Large \it = \frac{ \sqrt{10} + 2 - \bigg( \sqrt{10} - 2 \bigg) }{ \bigg( \sqrt{10} - 2 \bigg) \bigg( \sqrt{10} + 2 \bigg)} = \frac{4}{10 - 4} = \frac{2}{3} ; \\ \boxed{ \boxed{ \underline{ \huge \it \: otvet : \Huge \: \frac{2}{3} }}} \huge.$