x²-x-1=0x²-x+1/4-1/4-1=0(x-1/2)²=5/4x-1/2=±√5/2x=1/2±√5/2x=(1±√5)/2望采纳,谢谢!
算错了,重新算一下ax²+bx+c=0x=(-b±根号(b²-4ac))/2ax=(1±根号5)/2
a=4 b=-12 c=-1 ∷=b²-4ac=144+16=160x=(-12±√160)/8x2=(√160-12)/8x2=(√160+12)/8谢谢!采纳!