So basically im supposed to use source transformation to solve this problem , so i managed to transform all voltage sources into current sources with resistors in parallel and ended up with 2,6 k resisors in parralel with a 4 mA source so Io= 1mA , but then i tried to solve this problem using nodal analysis and i cant seem to know what to do if i pick ground node to be the bottom node , then i'd have two nodes in this circuit, right?, i cant seem to figure out how to deal with the 2 adjacent voltage sources, i know supernodes must be involved but i cant seem to be able to right their equation , any help is appreciated and thanks in advance.