m2-1/m2-2m+1÷(m-1-m+1/m-1)
=(m-1)(m+1)/(m-1)² ÷[(m-1)²-(m+1)]/(m-1)
=(m+1)/(m²-2m+1-m-1)
=(m+1)/(m²-3m)
=(√3+1)/(3-3√3)
=-1/3×(√3+1)²/2
=-(4+2√3)/6
=-(2+√3)/3