Question

Answer 1

\(R_{23}=\dfrac{R_2.R_3}{R_2+R_3}=\dfrac{15.18}{15+18}=\dfrac{90}{11}\left(\Omega\right)\)

\(R_{tđ}=R_1+R_{23}=20+\dfrac{90}{11}=\dfrac{310}{11}\left(\Omega\right)\)

Answer 2

Rtđ=R₁+R₂₃=20+\(\dfrac{15.18}{15+18}\)=20+\(\dfrac{90}{11}\)=\(\dfrac{310}{11}\)(Ω)