I1=P1/U1=3W/6V=0.5A I2=P2/U2=1.5A
R1=U1^2/P1=12欧 R2=U2^2/P2=4欧
U=I1(R1+R2)=8V
P1'=3W P2'=1W
标有6v3w灯泡更亮些