因式分解，快

2x^2-2x+1=4/5
2x^2-2x+1-4/5=0
2x^2-2x+1/5=0
4x^2-4x+2/5=0
4x^2-4x+1-3/5=0
(2x+1）^2-3/5=0
(2x+1-√15/5)(2x+1+√15/5)=0

x=(√15-5）/10或x=-(√15+5）/10

2x^2-2x+1=4/5
2x^2-2x+1/5=0
10x^2-10x+1=0
{x-[(5+根号15)/10]}{x-[(5-根号15)/10]}=0

2x^2-2x+1=4/5
2x^2-2x+1/2+1/2=4/5
2(x^2-x+1/4)+1/2=4/5
2(x-1/2)^2=4/5-1/2=3/10
(x-1/2)^2=3/20
x-1/2=±√(3/20)
x=±√(3/20)+1/2
=±√15/10+1/2