1.若x^2+3x+1=6则x^2+1/x^2=?2.若2x/(x^2-4)=A/(x+2)+B/(x-2) 则A=?B=?

1)x^2+3x+1=6?……估计6是0不是我也不会x^2+3x+1=0(同除x）x+3+1/x=0x+1/x=-3x^2+1/x^2+2=9x^2+1/x^2=72)2x/(x^2-4)=2x/(x+2)(x-2)=1/(x+2)+1/(x-2)=A/(x+2)+B/(x-2) 比较得A=1,B=1