Question 1208435
1/R = (1/a) + (1/b) + (1/c)


{{{1/R = (1/a) + (1/b) + (1/c)}}}



{{{Rabc(1/R)=(Rabc)(1/a+1/b+1/c)}}}

{{{abc=Rbc+Rac+Rab}}}

{{{abc=R(bc+ac+ab)}}}

{{{highlight(R=(abc)/(bc+ac+ab))}}}