question_answer

If \[x=\frac{5-\sqrt{21}}{2},\] then find the value of \[\left( {{x}^{3}}\,+\,\frac{1}{{{x}^{3}}} \right)\,-\,5\,\left( {{x}^{2}}\,+\,\frac{1}{{{x}^{2}}} \right)\,+\,\left( x\,+\,\frac{1}{x} \right)\]

A)  1                                

B)  110

C)  23                               

D)  0

E)  None of these