3x(2x+1)=4x+2 6x^2+3x=4x+26x^2-x-2=0(3x-2)(2x+1)=03x-2=0 x1=2/32x+1=0 x2=-1/2(x-4)^2=（5-2x)^2x^2-8x+16=25-20x+4x^23x^2-12x+9=0x^2-4x+3=0(x-3)(x-1)=0x1=3 x2=1 .