zhuwenzhe
幼苗
共回答了22个问题采纳率:90.9% 举报
1 x²+5x-1=0
(x+5/2)²=1+25/4
(x+5/2)²=29/4
x+5/2=±√29/2
x=(-5±√29)/2
2 2x²-4x-1=0
x²-2x=1/2
(x-1)²=3/2
x-1=±√6/2
x=(2±√6)/2
3 四分之一x²-6x+3=0
x²-24x=-12
(x-12)²=144-12
(x-12)²=132
x-12=±2√33
x=12±2√33
4 x²-x+6=0
x²-x=-6
(x-1/2)²=-6+1/4
1年前
6