(x²-3x+3)/(x-2)
=(x²-2x-x+2+1)/(x-2)
=x-1+1/(x-2)
=(x-2)+1/(x-2)+1
>=2+1=3
∴（x^2-3x+3）/(x-2)>=3 （x＞2）=(x²-2x-x+2+1)/(x-2)是怎么转化成x-1+1/(x-2)的啊？？x²-2x-x+2+1=x(x-2)-(x-2)+1