3y+7/(y-1)(y-2)=A/(y-1)+B/(y-2),则A=( )B=( )若x+1/x=3,则x²/x^4+x²+1=( )

问题描述:

3y+7/(y-1)(y-2)=A/(y-1)+B/(y-2),则A=( )B=( )
若x+1/x=3,则x²/x^4+x²+1=( )