(Z1-1)(1+i)=1-iZ1-1=(1-i)/(1+i)Z1-1=-iZ1=1-i设Z2=a+2iZ1Z2=(1-i)(a+2i)=a+2i-ai+2=(a+2)+(2-a)i因为Z1Z2是实数，a=2Z2=2+2i
