# Thread: solve for the resistance of each resistor.

1. ## solve for the resistance of each resistor.

when two resistors of resistances R(1) and R(2) (the numbers are the subscripts) are connected in parallel, their combined resistance is
R(1) R(2) / R(1) + R(2). two resistors are found to have a combined resistance of 10 ohms (thats just a variable, im assuming) when connected in series, and 2 ohms when connected in parallel. what is the resistance of each? it would be best to use X as the variable. thanks!

2. $\displaystyle \left\{ \begin{gathered} \left( {\frac{1} {{R_1 }} + \frac{1} {{R_2 }}} \right)^{ - 1} = 2 \hfill \\ R_1 + R_2 = 10 \hfill \\ \end{gathered} \right.$

two equations in two unknowns...

3. Originally Posted by Peritus
$\displaystyle \left\{ \begin{gathered} \left( {\frac{1} {{R_1 }} + \frac{1} {{R_2 }}} \right)^{ - 1} = 2 \hfill \\ R_1 + R_2 = 10 \hfill \\ \end{gathered} \right.$

two equations in two unknowns...

well how would i solve that?

4. for example you could isolate R1 from the s3econd equation and plug it into the first...

5. Originally Posted by Peritus
for example you could isolate R1 from the s3econd equation and plug it into the first...
but what about then the two are connected in parallel it is 2 ohms?

6. Originally Posted by polakio92
but what about then the two are connected in parallel it is 2 ohms?
nevermind, u wrote that in in the original equation. sorry