The answer is (C) [tex]R_2=\frac{R_TR_1}{(R_1-R_T)}[/tex]
We need to make [tex]R_2[/tex] the subject of the formula [tex]R_T=\frac{R_1R_2}{R_1+R_2}[/tex]
First remove the denominator by multiplying both sides by the binomial [tex](R_1+R_2)[/tex]
[tex]R_T\times (R_1+R_2)=\frac{R_1R_2}{R_1+R_2}\times(R_1+R_2)\\\\R_TR_1+R_TR_2=R_1R_2[/tex]
Arrange all terms containing [tex]R_2[/tex] on one side
[tex]R_1R_2-R_TR_2=R_TR_1[/tex]
Factor out [tex]R_2[/tex] from the LHS
[tex]R_2(R_1-R_T)=R_TR_1[/tex]
Finally, divide both sides by the binomial [tex](R_1-R_T)[/tex] to leave [tex]R_2[/tex]
[tex]R_2(R_1-R_T)\times\frac{1}{(R_1-R_T)}=R_TR_1\times\frac{1}{(R_1-R_T)}\\\\R_2=\frac{R_TR_1}{(R_1-R_T)}[/tex]
Learn more about change of subject of formula here: https://brainly.com/question/343660
