第一題

I1X10ohm+45v=V1
(10A-I1)X30ohm+(-20I1)=V1

聯立可得V1=525/6 =87.5v

I1=(V1-V3)/10=(87.5v-45v)/10ohm = 4.25A

I1+I2=45/5=9A
I2=9A-4.25A=4.75A

二十幾年前會，現在也會