解:3x²+6x-4=0
3(x²+2x)-4=0
3[(x+1)²-1]-4=0
3(x+1)²-3-4=0
3(x+1)²=7
(x+1)²=7/3
x+1=±√21 /3
x=-1±√21 /3.
x1=-1+√21 /3,x2=-1-√21 /3.
仅供参考!!
3x²+6x-4=0
3x²+6x+3-7=0
3(x+1)²-7=0
(x+1)²=7/3
x=正负 7/3的平方根-1
3x²+6x-4=0
x²+2x-4/3=0
x²+2x+1-1-4/3=0
(x+1)²-7/3=0
[x+1+√(7/3)][x+1-√(7/3)]=0
[x+1+√21/3][x+1-√21/3]=0
x=-1-√21/3或x=-1+√21/3