(x^2-2x+3)^2 = 4x^2-8x + 9
(x^2-2x+3)^2 - (4x^2-8x) - 9 = 0
(x^2-2x)^2 + 6(x^2-2x) + 9 - 4 (x^2-x) - 9 = 0
(x^2-2x)^2 + 2(x^2-2x) = 0
(x^2-2x)(x^2-2x+2) = 0
x(x-2)【(x-1)^2+1】 = 0
∵(x-1)^2+1＞ 0
∴x(x-2)=0
∴x1=0,x2=2