(1) 9x²-6x+1=0 (3x-1)²=0 x=1/3
(2)4x²-4x+1=0 (2x-1)²=0 x=1/2
(3) x²+2√3x=0 x(x+√3)=0 x①=0 x②=-√3
(4) 2x²-3x+6=0 无解
(5) x²-5x+1 x①,②=(5±√21)/2
(1) 9x²-6x+1=0 (3x-1)²=0 x=1/3
(2)4x²-4x+1=0 (2x-1)²=0 x=1/2
(3) x²+2√3x=0 x(x+√3)=0 x①=0 x②=-√3
(4) 2x²-3x+6=0 无解
(5) x²-5x+1 x①,②=(5±√21)/2