[(m-n/m^2-2mn+n^2)-(mn+n^2/m^2-n^2)]*(mn/n-1)={[m-n/(m-n)^2)]-[n(m+n)/(m+n)(m-n)]*(mn/n-1)=[1/(m-n)- n/(m-n)] * mn/(n-1)=(1-n)/(m-n) * mn/(n-1)= -(mn)/(m-n)因为mn =(-√3-2)(-√3+2) = -1m-n = (-√3-2)-...