x^2-16x-1=0
x^2-x=16x 两边除x
x-1/x=16 平方
x^2-2+1/x^2=256
x^2+1/x^2=258
(x^2+1/x^2)(x-1/x)
=x^3-x+1/x-x^3=258*16=4128
x^3-1/x^3=4128+x-1/x=4128+16=4144