Steps to determine the node
 voltages:
 
 1.Select a node as the
 reference node.
 2.Assign voltages
 v1,v2,…,vn-1 to the remaining n-1 nodes. The voltages are referenced with
 respect to the          reference node. 
 3.Apply KCL to each of the
 n-1 non-reference nodes. Use Ohm’s law to express the branch currents in terms of
 node voltages. 
 4.Solve the resulting
 simultaneous equations  to obtain the unknown
 node voltages.