Question

please answer ittttt​

Answer 1

$\huge \fbox \green{❤Solution:}$

$x = 3 - \sqrt{8}$

$∴ \frac{1}{x} = \frac{1}{3 - \sqrt{8} }$

$\fbox{Now,}$

$x + \frac{1}{x} = 3 - \sqrt{8} + 3 + \sqrt{8} = 6$

$⇒ {x}^{3} + \frac{1}{ {x}^{3} } = (x + \frac{1}{x} {)}^{3} - 3x \frac{1}{x} (x + \frac{1}{x} )$

$⇒ {x}^{3} + \frac{1}{ {x}^{3} } = 216 - 18$

$⇒ \frac{1}{x} = 3 + \sqrt{8}$

$⇒ {x}^{3} + \frac{1}{ {x}^{3} } = (6 {)}^{3} - 3(6)$

$⇒ {x}^{3} + \frac{1}{ {x}^{3} } = 198$

$\text{ANSWER ᵇʸ ⁿᵃʷᵃᵇ⁰⁰⁰⁸}$