(x+yi)/(1+i)=3i(x+yi)=3i(1+i)=3i-3故x=-3,y=3x+y=0
x/(1+i)+yi=3ix(1-i)/2+yi=3ix/2+(y-x/2)i=3则x/2=0 (y-x/2)=3得 y=3所以 x+y=3
