Question

if x+1/x=7 then find x³+1/x³

Answer 1

Your answer is ---

Given,

$x + \frac{1}{x} = 7$

We have ,

${x}^{3} + \frac{1}{ {x}^{3} } = {(x + \frac{1}{x}) }^{3} - 3(x + \frac{1}{x}) \\ \\ = {7}^{3} - 3 \times 7 \\ \\ = 373 - 21 \\ \\ = 352$



【 Hope it helps you 】