用配方法解下面的方程（1）x^2+14x+2=0 （2）x^2+4x-3=0 (3)3z^2-4z-7=0 （4）2-1

（1）x^2+14x+2=0
x^2+14x+49=47
(x+7)^2=47
x+7=±√47
x=-7±√47
（2）x^2+4x-3=0
x^2+4x+4=7
(x+2)^2=7
x+2=±√7
x=-2±√7
(3)3z^2-4z-7=0
z^2-4/3z-7/3=0
z^2-4/3z+4/9=4/9+7/3
(z-2/3)^2=25/9
z-2/3=±5/3
z=-1,z7/3
（4）2-1/3x^2=5/3x
x^2+5x=6
x^2+5x+25/4=6+25/4
(x+5/2)^2=49/4
x+5/2=±7/2
x=-6,x=1
(5)0.1x^2+x+0.5=0
x^2+10x+5=0
x^2+10x+25=20
(x+5)^2=20
x+5=±2√5
x=-5±2√5
(6)根号2x^2-2x-根号2=0
x^2-√2x-1=0
x^2-√2x+1/2=3/2
(x-√2/2)^2=3/2
x-√2/2=±√6/2
x=(√2±√6)/2