1、3-27x²=0 x^2=9 x=3 x=-3
2、4（1-x）²-9=0 (1-x)^2=9/4 1-x=+-3/2 x=5/2 x=-1/2
3、x²-5x+6=0 (x-2)(x-3)=0 x=2 x=3
4、8x²-2=4x 8x²-4x-2=0 4x²-2x-1=0 4x²-2x-1/4 -3/4=0 (2x-1/2)^2=3/4
(2x-1/2)=+-根号3/2 x=(根号3+1)/4 x=(1-根号3)/4
1、3-27x²=0 x^2=9 x=3 x=-3
2、4（1-x）²-9=0 (1-x)^2=9/4 1-x=+-3/2 x=5/2 x=-1/2
3、x²-5x+6=0 (x-2)(x-3)=0 x=2 x=3
4、8x²-2=4x 8x²-4x-2=0 4x²-2x-1=0 4x²-2x-1/4 -3/4=0 (2x-1/2)^2=3/4
(2x-1/2)=+-根号3/2 x=(根号3+1)/4 x=(1-根号3)/4