甲R=220×220/40=1210乙R=220×220/100=484甲乙I=220/(1210+484)=0.12987012987012987012987012987013甲P=I×I×R=20.408163265306122448979591836735乙P=I×I×R=8.1632653061224489795918367346776
先根据R=U平方/P算出R1R2,I(R1+R2)=220,算出i,P=I平方乘以R