In the picture u can see there are two voltage sources, Im confused one how to apply KVL to this. the book has this problem worked out and they get -12+4i+2v-4+6i=0 but i dont get this , i get this -12+4i+2v-4v-6i=0 and solutions isnt the same, what is my problem? For some reason there getting +6i and im getting -6i. WHy does this happen. Can someone please explain clearly, how to solve something like this, and for future circuits ?