MHB Linear Applications: Electrical Networks

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The discussion revolves around solving a circuit problem to determine branch currents using assigned variables and equations. The user created three equations based on their circuit analysis but found a discrepancy between their calculated results and the book's solutions. The user’s derived currents are I1=35/13, I2=20/13, and I3=15/13, while the book states I1=5/7, I2=20/7, and I3=15/7. Another participant suggests that the user's equations are correct and that the book's solutions likely pertain to a different problem with different resistor values. The conclusion indicates that the initial setup of equations is not the issue, but rather the book's provided answers.
Pull and Twist
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So I am having difficulty with the following problem;

Determine the currents in the various branches.

View attachment 5184

So I went ahead and assigned I names to the various branches and drew in flow directions to help me visualize the problem better.

From there I created the following three equations;

I1=I2+I3
2I1+3I2=10
2I1+4I3=10

Which I then put in a matrix and was able to reduce for the following solutions;

I1=35/13
I2=20/13
I3=15/13

The problem is that the book states that I should be getting;

I1=5/7
I2=20/7
I3=15/7

Where am I going wrong in setting up my equations? I know I'm not messing up going to RREF form cause my calculator is giving me the same answer. I figure I must be screwing up the initial equations.
 

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Hi PullandTwist,

I believe your equations and solution are fine.
The stated book solution is wrong.
It looks as if it belongs to a similar problem with different resistors.
For instance with resistors $2\ \Omega, 2\ \Omega, 6\ \Omega$ and voltage $10\ \textrm{V}$.
 
Here is a little puzzle from the book 100 Geometric Games by Pierre Berloquin. The side of a small square is one meter long and the side of a larger square one and a half meters long. One vertex of the large square is at the center of the small square. The side of the large square cuts two sides of the small square into one- third parts and two-thirds parts. What is the area where the squares overlap?

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