Three Unknown Resistances: Solving for Unknowns in a System of Equations

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The discussion focuses on solving for three unknown resistances, R1, R2, and R3, using a system of three equations derived from electrical circuit principles. The equations provided are: 1/(R2+R3) + 1/R1 = 1/670, 1/(R1+R3) + 1/R2 = 1/679, and 1/(R1+R2) + 1/R3 = 1/1349. The user suggests that taking the least common multiple (LCM) of the equations simplifies the problem, leading to a more manageable equation: R1(R2+R3)/670 = R2(R1+R3)/679 = R3(R1+R2)/1349. This approach effectively reduces complexity and aids in finding the unknown resistances.

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I need to find three unknown resistances given the following three equations:

<br /> \frac{1}{R_2+R_3} + \frac{1}{R_1} = \frac{1}{670}<br />

<br /> \frac{1}{R_1+R_3} + \frac{1}{R_2} = \frac{1}{679}<br />

<br /> \frac{1}{R_1+R_2} + \frac{1}{R_3} = \frac{1}{1349}<br />

I figured since there are three unknowns and three equations it is possible, but I can't see how its done.
 
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Sorry, I'm in a slight hurry, but it may be done in this way,

If you take LCM in all the three equations, you find that the numerator of the LHS becomes equal. If the denominators are take to the RHS, you'll get something like

\displaystyle \frac{R_1(R_2+R_3)}{670}=\frac{R_2(R_1+R_3)}{679}=\frac{R_3(R_1+R_2)}{1349}

The above equation might help as it is much simpler. Maybe you can try solving the above.

Regards,
Sleek
 
Wow, thanks heaps. Took me a while to figure out how you got that :) It should be a lot easier now.
 

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