lim06192011-05-14TA获得超过8.1万个赞关注由x²-3x+1=0,同除以x:x-3+1/x=0,∴x+1/x=3,(x+1/x)²=9,x²+2+1/x²=9,x²+1/x²=7,(x²+1/x²)²=49,x^4+2+1/x^4=49,∴x^4+1/x^4=47.2.由(3x²-8x-3)÷(x-a)=(3x+1)(x-3)÷(x-a)当a=3时:(3x²-8x-3)÷(x-a)=3x+1.