A source resistor and a load share one loop, so the same current sets both voltage drops and both power terms. Equal source and load resistances give a clean half-and-half voltage split, and the rendered 24 V row at 3 A drops 12 V on each side with 36 W plus 36 W equal to 72 W of source power exactly for the ideal DC model; real circuits add resistor tolerance, source impedance, loading, heating, supply limits, contact resistance, temperature drift, and voltage, current, and power measurement uncertainty.
A source resistor and a load share one loop, so the same current sets both voltage drops and both power terms. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
A source resistor spends part of the source voltage
This is still a DC circuit model. The source resistor is an explicit element, so the load only receives the voltage left after the source-resistor drop.
Vs=Vsource resistor+VL
Each row splits voltage across source and load
Equal source and load resistances make a clean half-and-half voltage split, but the current is still computed from the total series resistance.
For the rendered row, the source provides 72 watts. The source resistor and load each receive 36 watts.
24V⋅3A=72W,36W+36W=72W
Every ampere and every watt has one accounted path
The source resistor is not a vague loss term. It is a circuit element with a voltage drop, a current, and a power term that must appear in the same ledger as the load.