Answer:
see explanation
Step-by-step explanation:
A - eliminate the fractions → d
B
[tex]\frac{1}{r_{1} }[/tex] + [tex]\frac{1}{r_{2} }[/tex] = [tex]\frac{1}{R}[/tex]
multiply through by Rr₁r₂ to clear the fractions
Rr₂ + Rr₁ = r₁r₂ ( factor out R from each term on the left side )
C
R(r₂ + r₁) = r₁r₂ ← divide both sides by (r₂ + r₁)
R = [tex]\frac{r_{1}r_{2} }{r_{2}+r_{1} }[/tex]
