5 , 6 , 7.
Определите эквивалентное сопротивление относительно точек А и В

5) R34=R3*R4/(R3+R4)=3/2=1.5

R234=R2*R34/(R2+R34)=2*15/(2+1.5)=0.86

Ro=R1+R234+R5=1+0.86+4=5.86

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6) R45=R4*R5/(R4+R5)=2*6/(2+6)=1.5

R345=R3+R45=1+1.5=2.5

R12=R1*R2/(R1+R2)=10*5/(10+5)=3.3

Ro=R12*R345/(R12+R345)=3.3*2.5/(3.3+2.5)=1.42

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7) R23=R2*R3/(R2+R3)=5*2/(5+2)=1.43

R234=R23+R4=1.43+3=4.43

Ro=R1*R234/(R1+R234)=10*4.43/(10+4.43)=3

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