y=(2x-1)/(x+1)yx+y=2x-1x(y-2)=-y-1x=(y+1)/(2-y)反函数的定义域是原函数值域y不为2即值域
y=(2x+2-3)/(x+1)=2-3/(x+1)3/(x+1)≠0y≠2(-∞,2)∪(2,+∞)
