Please see the attachment for the complete question and diagram. Thanks.
This is a question that requires a voltage divider, Kirchoff's node law, series and parallel resistor equivalents, and Ohm's law.
The circuit is
ground - ig - 10W || (8W -14W - 18W) - ground
The current in the triple series resistors must be the same (ia). Therefore, we can write the equivalent circuit by ...
This solution is provided in 273 words. It uses Kirchoff's law and Ohm's law to solve the problem. Calculations are used with short explanations to solve the problems.