Question

if
$x + \frac{1}{x} = 5$
find the value of
$x {}^{3} + \frac{1}{x \frac{3}{} }$

​

Answer 1

Step-by-step explanation:

$= > x + \frac{1}{x} = 5 \\ \\ = > {(x + \frac{1}{x} )}^{3} = {5}^{3} \\ \\ = > {x}^{ 3} + { (\frac{1}{x}) }^{3} + 3(x + \frac{1}{x}) = 125 \\ \\ = > {x}^{3} + \frac{1}{ {x}^{3} } + 3 \times 5 = 125 \\ \\ = > {x}^{3} + \frac{1}{ {x}^{3} } + 15 = 125 \\ \\ = > {x}^{3} + \frac{1}{ {x}^{3} } = 110$