1. x²-2x-2=0
(x-1)²=2+1
(x-1)²=3
x-1=±√3
x=1±√3
2. 6x²-x-12=0
6(x²-x/6)=12
x²-x/6=2
(x-1/12)²=2+1/144
(x-1/12)²=289/144
x-1/12=±√289/12
x=(1±√289)/12
1.x^2-2x-2=x^2-2x+1-3=0
所以x^2-2x+1=3
即(x-1)^2=3
从而x-1=sqrt(3)或x-1=-sqrt(3)
因此x=1+sqrt(3)或x=1-sqrt(3)
2. 6x^2-x-12=0配方得到6(x-1/12)^2=12+1/24=289/24
从而(x-1/12)^2=289/144
所以x-1/12=17/12或x-1/12=-17/12
所以x=18/12=3/2或x=-4/3.