Problem 3.20 - Nodal analysis with 2 super nodes- Fundamentals of Electric Circuits

Alexander & Sadiku, 5th Edition
Circuit Theory - Electric Circuits - Nodal Analysis - Kirchoffs Current Law- KCL- Finding Node voltages in a circuit- Engineering - Circuit analysis - Super node - Kirchoff Voltage law - KVL
Complex Electric Circuits - 2 number of Super nodes
1. nodal analysis - KCL - Kirchoff's Current law
2. Super node - KVL - Kirchoff's Voltage Law
3. KCL = sum of incoming currents = sum of leaving currents
4. Write Current equation
5. Apply ohm's law : Current = potential difference /resistance
What is to be done before start of solving the problem?
1.Mark the nodes
2. Mark the node voltages
3. Mark arbitrary current directions