1）=a(a-b)x(b-a分之ab) 2)= (x+1)(x-1)分之x+3乘以 （x+3)(x-1)分之（x-1) ² =a(a-b)x(-a-b分之ab) =x+1分之1乘以x-1分之x-1=ax(-ab) =x+1分之1乘以1=-a²b =x+1分之1应该对的……看我打这么辛苦给个辛苦...1的X是?_?意思是乘号……我不懂打明白咯