Question

x-1/x=3 what is x^3-(1/x)^3

Answer 1

It Is Simple That
We Know That
${(a - b)}^{3} = {a}^{3} - {b}^{3} - 3(ab(a + b))$
Then We Take a=x and b=1/x
Then
${(x - ( \frac{1}{x}) }^{3} = {x}^{3} - { \frac{1}{x} }^{3} - 3(x( \frac{1}{x} )(x - \frac{1}{x} ))$
${x}^{3} - { \frac{1}{x} }^{3} = {(x - \frac{1}{x} )}^{3} + 3(3)$
=3^3+3^2=>27+9=36