要标序哦

要标序哦
要标序哦
 

要标序哦
2 (1)（a+b）/(a+b)=1
(2)a/(a+1)-1(a+1)=(a-1)/（a-1）=1
剩下的马上,先给你前两个的.
(3)
=x^2/(x-2y)-4y^2/(x-2y)
=(x^2-4y^2)/(x-2y)
=(x+2y)(x-2y)/(x-2y)
=x+2y
(4)
=(3a-b-4a+3b)/(a-2b)
=(-a+2b)/(a-2b)
=-1
3(1)选择C.
=(a+b-2a)/(b-a)+2b/(a-b)
=1+2b/(a-b)
=(a+b)/(a-b)
希望帮得到你O(∩_∩)O~