x^2-6x-6=0
x^2-6x+9=15
(x-3)^2=15
x-3=正负根号15
则x=3加根号15或者3减根号15
x^2-2x-1=0
x^2-2x+1=2
(x-1)^2=2
x-1=正负根号2
则x=1加根号2或者1减根号2
x(x+8)=16
x^2+8x-16=0
x^2+8x+16=32
(x+4)^2=32
(x+4)=正负根号32(即正负4倍根号2)
则x=-4加4倍根号2或者-4减4倍根号2
(1)x²-6x-6=0
解:x²-6x+9=15
(x-3)²=15
x-3=±√15
x=3±√15
(2)x²-2x-1=0
解:(x-1)²=2
x-1=±√2
x=1±√2
(3)x(x+8)=16
x²+8x+16=32
(x+4)²=32
x+4=±4√2
x= -4±4√2
(1)x²-6x-6=0
(x-3)^2=15
x-3=±√15
x=3±√15
(2)x²-2x-1=0
(x-1)^2=2
x-1=±√2
x=1±√2
(3)x(x+8)=16
(x+4)^2=32
x+4=±√32
x=-4±4√2
(1)x²-6x=6
x²-6x+9=6+9
(x-3)²=15
x-3=±√15
x1=3+√15 x2=3-√15
(2)x²-2x=1
x²-2x+1=1+1
(x-1)²=2
x-1=±√2
x1=1+√2 x2=1-√2
(3)x²+8x=16
x²+8x+16=16+16
(x+4)²=32
x+4=±4√2
x1=-4+4√2 x2=-4-4√2