-1小于或等于y-2/y-1小于或等于1为什么解出来有y>1,y大于或等于3/2或y1,y大于或等于3/2或y1,y大于或等于3/2或y

Question

-1小于或等于y-2/y-1小于或等于1 为什么解出来有y>1 ,y大于或等于3/2或y1 ,y大于或等于3/2或y1 ,y大于或等于3/2或y

Answer 1

分母不为0所以y不等于1,当y>1时
-1<=(y-2)÷（y-1）<=1
-(y-1)<=y-2<=1
1-y)<=y-2<=1,
1-y)<=y-2,3<=2y,y>=3/2,y-2<=1,y<=3.即3/2<=y<=3
当y<1时
y-1>=y-2>=-y+1
y-2>=-y+1,2y>=3,y>=3/2.不成立.
所以3/2<=y<=3