Question

X+ 1/x =root 7, find x3 + 1/x3.

Answer 1

hope this will help you plzz like this

Answer 2

$given \\ x + \frac{1}{x} = \sqrt{7} \\ \\ \\ {x}^{3} + \frac{1}{ {x}^{3} } = ( {x + \frac{1}{x} })^{3} - 3(x + \frac{1}{x} ) \\ = ( { \sqrt{7} })^{3} - 3 \sqrt{7} \\ = 7 \sqrt{7} - 3 \sqrt{7} \\ = 4 \sqrt{7}$