Hello,

I have the following equation:

v1/v2 = R2/R1+R2

How do we solve for R2?

I don't know how to isolate R2 on one side of the equation. All help is appreciated?

thanks

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- Mar 4th 2013, 09:10 AMsimplyComplexDon't know how to factor?
Hello,

I have the following equation:

v1/v2 = R2/R1+R2

How do we solve for R2?

I don't know how to isolate R2 on one side of the equation. All help is appreciated?

thanks - Mar 4th 2013, 09:29 AMPlatoRe: Don't know how to factor?
[QUOTE=simplyComplex;773431]I have the following equation:

v1/v2 = R2/R1+R2

How do we solve for R2?/QUOTE]

Is it $\displaystyle \frac{v_1}{v_2}=\frac{R_2}{R_1+R_2}~?$

Because you actually posted $\displaystyle \frac{v_1}{v_2}=\frac{R_2}{R_1}+R_2$

Which is it? - Mar 4th 2013, 09:53 AMHallsofIvyRe: Don't know how to factor?
If it is $\displaystyle \frac{v_1}{v_2}= \frac{R_2}{R_1+ R_2}$, start by multiplying both sides by $\displaystyle v_2(R_1+ R_2)$ to get $\displaystyle v_1(R_1+ R_2)= v_1R_1+ v_1R_2= v_2R_2$.

If it is $\displaystyle \frac{v_1}{v_2}= \frac{R_2}{R_1}+ R_2$, start by writing $\displaystyle R_2$ as $\displaystyle \frac{R_1R_2}{R_2}$ so you have $\displaystyle \frac{v_1}{v_2}= \frac{R_2}{R_1}+ \frac{R_1R_2}{R_1}= \frac{R_2+ R_1R_2}{R_1}$ and now multiply by $\displaystyle R_1v_2$. - Mar 4th 2013, 10:47 AMsimplyComplexRe: Don't know how to factor?
Ooops I'm sorry.... Its:

v1/v2 = R2/(R1 + R2)

Quote:

start by multiplying both sides by v2(R1 + R2) to get....

v1/v2 = R2/(R1 + R2)

so when you say cross multiply... do you mean like this:

(R1 + R2) (v1/v2) = (R2/(R1+R2)) (v2)

v1(R1 + R2) = R2v2

v1R1 + v1R2 = R2v2

So now, R2 is on both sides, what I really need is to isolate R2 on one side!!!!

So what is the next step?

thanks - Mar 4th 2013, 11:14 AMsimplyComplexRe: Don't know how to factor?
Okay I think I got it:

v1/v2 = R2/(R1 + R2)

(R1 + R2) (v1/v2) = (R2/(R1+R2)) (v2)

v1(R1 + R2) = R2v2

v1R1 + v1R2 = R2v2

v1R1 = R2v2 - v1R2

v1R1 = R2(v2 - v1)

v1R1/(v2-v1) = R2(v2 - v1)/ (v2 - v1)

R2 = v1R1/(v2-v1)

Thanks!