Question

please help me to solve these questions please! don't say wrong options​

Answer 1

$\red{x = \frac{1}{3 - \sqrt{8} } \: \: and \: \: y = \frac{1}{ \sqrt{8} - \sqrt{7 } } } \\ \blue{so \: (x - y) {}^{2} = \: ?} \\ \\ \green{\blue{so \: (x - y) {}^{2} } = ( \frac{1}{3 - \sqrt{8} } \: \: - \frac{1}{ \sqrt{8} - \sqrt{7 } }) {}^{2} } \\ {(x - y) {}^{2} } = ( \frac{1}{3 - \sqrt{8} } \: \: - \frac{1}{ \sqrt{8} - \sqrt{7 } }) {}^{2} \\ \red{= 2(8 - 3 \sqrt{7} )}$