Question

please explain as I am not able to understand it ​

Answer 1

${\huge{\underline{\mathcal{\purple{Solution}}}}}$

Step-by-step explanation:

$x = 2 - \sqrt{3} \\ \frac{1}{x} = \frac{1}{2 - \sqrt{3} } \\ rationalising \: \: denominator \\ \frac{1}{x} = \frac{1}{2 - \sqrt{3} } \times \frac{2 + \sqrt{3} }{2 + \sqrt{3} } \\ = \frac{2 + \sqrt{3} }{ {2}^{2} - { (\sqrt{3} })^{2} } = \frac{2 + \sqrt{3} }{4 - 3} \\ \frac{1}{x} = 2 + \sqrt{3} \\ \\ now \: put \: values \\ (2 - \sqrt{3} - 2 - \sqrt{3} ) {}^{3} \\ = (- 2 \sqrt{3} ) {}^{3} \\ = - 8 \sqrt{3} {}^{3}$

I think my put values calculations are wrong but starting is right