27X²-18X+3=0
9X²-6X+1=0
(3X)²-2·3X·1+1²=0
(3X-1)²=0
3X-1=0
3X=1
X=1/34（x-3）²-x（x-3）=04(X²-6X+9)-X²+3X=03X²-24X+36+3X=03X²-21X+36=0X²-7X+12=0(X-4)(X-3)=0X=4或X=3