（2x+3）²-4（2x+3）+4=0 [(2x+3)-2]^2=02x+3-2=02x=-1x=-1/2.（x-3）²=（3x-2）²(x-3)^2-(3x-2)^2=0(x-3+3x-2)(x-3-3x+2)=0(4x-5)(-2x-1)=0x1=5/4x2=-1/2