Question 201628
x + 1/x =8
(x^2 +1 ) / x =8
x^2 +1 = 8x
x^2 -8x +1 =0
.
using  quadratic  eqn,, x= 7.873,,.127
,
substitute  either  in  
.
X^4 +(1/x^4) = 3842
.
checking  answers,  this  matches  (E) (8^4 -2^8 +2)