(1)将方程(3x-1) 2 =(x+1) 2 移项得, (3x-1) 2 -(x+1) 2 =0, ∴(3x-1+x+1)(3x-1-x-1)=0, ∴4x(2x-2)=0, ∴x(x-1)=0, 解得x 1 =0,x 2 =1. (2)∵2x 2 +x-
可得,a=2,b=1,c=
∴x=-
(3)∵x 2 -4x+1=0, ∴(x-2) 2 =3, 解得x 1 =2+
(4)设x 2 +x=y,则y 2 +y=6,y 1 =-3,y 2 =2, 则x 2 +x=-3无解, ∴x 2 +x=2, 解得x 1 =-2,x 2 =1. |