设y=2x-1,得
2y^2-5y-3=0
(2y+1）（y-3)=0
2y+1=0,y-3=0
y1=-1/2,y2=3
所以,x1=(y1+1)/2=(-1/2+1)/2=1/4
x2=(y2+1)/2=(3+1)/2=2