初二几道数学分式
(1)(m²-3m)/9-m²
(2)(3a²-ab)/(9a²-6ab+b²),其中a=3/4,b=-2/3
(3)(a²-b²)/(a²+ab)
(4)(a²+ab)/(a²+2ab+b²)
拜托速度TT