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## Homework Statement

An ohmic resistor (

*R*1 = 3.5 kΩ) and circuit element X are connected in series to a battery of unknown voltage

*V*0. Circuit element X is of unknown resistance. It is observed that the absolute value of the voltage across resistor

*R*1 is 5.0 V.

The battery voltage is measured and found to be equal to 8.0 V.

The resistance of X must be what?

## Homework Equations

V=IR

Found the current to be 0.0014 amps by doing 5.0 V/3500 kΩ

## The Attempt at a Solution

My trouble is that I have worked the problem, but have come up with 2 similar solutions that seem plausible.

Solution 1: 8V = 0.0014(R

_{1}+R

_{2}), solving for R

_{2}gives 2.21kΩ

Solution 2: Since the total voltage is 8 and R

_{1}is 5, R

_{2}must be 3. So then 3V = 0.0014(R

_{2)}, and solving for R

_{2}gives 2.14kΩ.

Both attempts are so close together that I have no idea which is right! Are they both more or less correct and one is just more accurate than the other?