(x²-4y²)/(4x²-8xy)
= (x+2y)(x-2y)/[4x(x-2y)]
=(x+2y)/(4x)
(a²-9)/(a²-6a+9)
=(a+3)(a-3)/(a-3)²
=(a+3)/(a-3)m²-3m+2/m²-m 3a³b³c/12ac² 不知为什么这么纠结(m²-3m+2)/(m²-m)=(m-2)(m-1)/[m(m-1)]=(m-2)/m 3a³b³c/(12ac²)=a²b³/(4c)