(y-1)(y+2)=2y(1-y)(y-1)(y+2)－2y(1-y)=0(y-1)(y+2)＋2y(y－1)=0(y－1)(y＋2＋2y)=0(y－1)(3y＋2)=0所以y－1=0y=1或者3y＋2=0y=﹣2／3不懂的还可以追问！满意请及时采纳！O(∩_∩)O
