simultaneous equations in a loop

I realized it's a simple one....I am a beginner.

I want to use a for loop in which contain a quadruple simultaneous equation like this

r1,r2,r3,r4,r5,r6,r7 are given

v1,v2,v3,v5 are unknown

for rt= -100:400 

(-5-v1)/r1+(v3-v1)/r4+(v2-v1)/rt=0

(v1-v2)/rt+(v3-v2)/r5+(5-v2)/r6=0

(5-v3)/r2+(v1-v3)/r4+(v5-v3)/r3=0

(0-v3)/r7+(v2-v3)/r5=0

end

And I want to plot v5/rt continuously

Anyone willing to help? Thanks!

Answer 1

[Walter Roberson]

No, you have 4 equations in 5 unknowns, v1, v2, v3, v4, v5. You can solve the 4 equations for any 3 of (v1, v2, v3, v4) together with v5, but you will find that v5 is expressed in terms of the one of the four variables you did not solve for.

You would need one more equation in order to be able to solve the system

[Matthew Yih]

sorry, forgot to mention v3=v4(op virtual ground)