Question

x-1/x=3
then
x^3+1/x^3=?

Answer 1

x-1=3x
2x=-1
x=-1/2

then putting the value of x in above eq.....

x^3+1/x^3
=(-1/2)^3+1/(-1/2)^3
=-1/8-1/1/8
=-1/8-8
=-1-64/8
=-65/8
here is your answer