Q:       Determine the voltages V_ac & V_db in give circuit.

Solution:    We  need to calculate V_ac & V_db. The circuit might be redrawn like

                        To determine Vac, the two loops will be acda & acba.

                                    Applying KVL equation for the loop acda

                                                V_ac + 8 - 12 =0

                                                V_ac = 4 V

                            By applying KVL equation for the loop acba will be

                                                V_ac + 6 - 10 = 0

                                                   V_ac = 4 V

                        Two loops for V_bd will be bdcb & bdab.

            Applying KVL equation for bdcb

                                                V_bd -8 +6 = 0

                                                         V_bd = 2 V

                                                Than    V_db = - 2V

                        Applying KVL equation for the loop bdab

                                                V_bd - 12 +10 =0

                                                  V_bd = 2 V