灯L1:R1= U P额1 = (6V)2 3W =12Ω灯L1正常发光电流:I1= P额1 U额1 = 3W 6V =0.5A灯L2:R2= U P额2 = (6V)2 6W =6Ω灯L2正常发光电流:I2= P额2 U额2 = 6W 6V =1A根据题意可知电路中的电流:I=0.5A∴U=I(R1+R2)=0.5A×(12Ω+6Ω)=9VP=UI=9V×0.5A=4.5W故答案为:9;4.5.