Derive the equation for total resistance of this circuit.

1. Combine the parallel-connect resistors, R₂ and R₃.

R_2,3 = R₂ || R₃

2. Include the series-connected resistor, R₁

R_T = R₁ + R_2,3

3 Finalize the equation

. R_T = R₁ + (R₂ || R₃)

The total resistance of this circuit is given by

. R_T = R₁ + (R₂ || R₃)