# Simultaneous Equations From Kirchhoff's Rules (1 Viewer)

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#### 00Formula00

1. The problem statement, all variables and given/known data
For a Lab report I have to solve for three unknown currents from Kirchoff's Rules equations using simultaneous equation algebra, and I'm completely stumped.

2. Relevant equations

From Loop and junction equations, the three equations that I have are

I1 + I2 = I3

I1= (-I3R3 - V2)/ (R2)

I2= (-I3R3+V1)/(R1)

3. The attempt at a solution

This is the farthest I have gotten, solving for I3. Once I have expression for this I will be able to plug back into the I1 and I2 equations fairly easy.

(-I3R3R2+ -I3R3R1+ -V2R1) / (R1R2)

= I3R1R2

Sorry If this is confusing. Thanks for any help in advance.

Last edited:

#### llello

You should just have to move all the terms with I3 to one side of the equation and factor out the current. That should give you an answer for I3.

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