I'm currently studying some basic algebra (Not sure what the equivalent is for the US etc) in school currently.
I'm having trouble with rearranging certain formulas.
I attempted to try and solve the questions below and I'll show my working ut but the answers are consistently incorrect.
- If $R = \dfrac{1}{R_1} + \dfrac{1}{R_2}$, what is the value of $R_1$ given that $R = 1.15$ and $R_2 = 2.30$?
I tried subtracting $\dfrac{1}{R_2}$ from $R$ seen here:
$$R - \frac{1}{R_2} = \frac{1}{R_1}$$ but realised that I'm not sure how to get $R_1$ by itself.
Also tried:
$$RR_2 = \frac{1}{R_1}$$
but unsure how to divide a fraction by a fraction.
Could someone help explain how to rearrange an equation like this?
$\endgroup$ 21 Answer
$\begingroup$We have $$R-\frac{1}{R_1}=\frac{1}{R_2}$$ $$\frac{RR_1-1}{R_1}=\frac{1}{R_2}$$ thus we obtain $$R_2=\frac{R_1}{R_1R-1}$$
$\endgroup$
