Combining the current sources of the given circuit. I've attached the circuit diagram below.
The Attempt at a Solution
Since the sources are in parallel I can just add up the values to get an equivalent source and same for the resistors. I'm curious in the proof of this fact. With two current sources and one resistor, I can see how the sources can be combined. But for cases like this, how does the 36A affect the 20 ohms resistor? How do the currents circulate in the circuit?