答：x^2-4x=1
两边同除以x得：x-4=1/x
x-1/x=4
所以：x^3-1/x^3
=(x-1/x)(x^2+1+1/x^2)
=4*[(x-1/x)^2+3]
=4*(4^2+3)
=4*19
=76
322是错误的