即m²+3m-1=0m²=-3m+1(m-3)/(3m²-6m)÷1/(m²-m-2)=(m-3)/3m(m-2)×(m²-m-2)=(m-3)/3m(m-2)×(m-2)(m+1)=(m-3)(m+1)/3m=(m²-2m-3)/3m=(-3m+1-2m-3)/3m=-5/3-2/3m
