设y=3x-1得
(1-3x)²+5(3x-1)-6=0
y²+5y-6=0
(y-1)(y+6)=0
y-1=0或y+6=0
y=1或y=-6
于是
3x-1=1或-6
3x=2或3x=-5
x=2/3或x=-5/3