The correct option is
C 724Given,
x+1x=4......(1).
Now squaring both sides we get,
x2+2+1x2=16
or, x2+1x2=14.......(2).
Now again cubing equation (1) we get,
x3+3.x.1x(x+1x)+1x3=64
or, x3+1x3=64−12
or, x3+1x3=52.......(3).
Now multiplying (2) and (3) we get,
x5+x+1x+1x5=728
or, x5+1x5=728−4=724. [ Using (1)].