How to find the current I of the load resistor in the circuit shown in the diagram using the branch current method or the nodal voltage method?

The ontology can be solved by the Nodal Voltage Method, the procedure is shown below.

Nodal Voltage Method

Nodal voltage is a method of calculating circuits for solving objects. Nodal voltage is the potential of the remaining nodes to the reference point after selecting any one node as a reference point for the circuit (this point is usually numbered "0") and making its potential zero.

Load Resistors

Large power supply equipment, medical equipment, electrical instruments and other products in use often need to absorb some of the excess power generated. The high power resistors used here are load resistors. Load resistors are also known as discharge resistors, braking resistors, brake resistors, and absorber resistors due to their special function.

These resistors have high power and are generally non-inductive power resistors. Non-inductance, ultra-low inductance is an important requirement for these products, in the process of absorbing power to the excess power discharge, if the resistor's inductance is too large, it is easy to generate shock, other components in the circuit, the power supply and the device itself to produce harm, and even directly burned many internal devices.