解
x²-6x=-5
x²-6x+9=4
(x-3)²=4
∴x-3=2或x-3=-2
∴x=5或x=1
y²+3y-2=0
y²+3y+9/4=2+9/4
(y+3/2)²=17/4
y+3/2=√17/2或y+3/2=-√17/2
y=-3/2+√17/2或y=-3/2-√17/2
a²=6a-1
a²-6a=-1
a²-6a+9=8
(a-3)²=8
∴a-3=2√2,或a-3=-2√2
∴a=3+2√2或a=3-2√2
x²-4x+3=0
x²-4x=-3
x²-4x+4=1
(x-2)²=1
x-2=1或x-2=-1
∴x=3或x=1
x²-5=2√3x
x²-2√3x=5
x²-2√3x+3=8
(x-√3)²=8
x-√3=2√2或x-√3=-2√2
∴x=√3+2√2
或x=√3-2√2都對(duì)的吧對(duì)啊