The question

I want to find the node voltages via KCL.

I seem to have forgotten what to do when there's a resistor in series with a voltage source. e.g. with node v3, to find the current entering the node from the lower branch, normally I'd use V/R (i.e. v3/5). However there's a 1v voltage source on the branch. How do I work with that?

Thanks.