若x^?+x^-?=9,则x^2+1/x^2=?若x^?-x^-?=3,则x^2+1/x^2=?
我打错了,应是若x^1/2+x^-1/2=9,则x^2+1/x^2=?
若x^1/2-x^-1/2=3,则x^2+1/x^2=?