According to Superposition theorem, one source should be retained at a time, deactivating remaining sources. Contributions due to individual sources are finally algebraically added to get the answers required. Fig. shows only one source retained and the resultant currents in all branches/elements. In Fig., other source is shown to be in action, with concerned currents in all the elements marked.
To get the total current in any element, two component-currents in Fig. and Fig. for the element are to be algebraically added. The total currents are marked on Fig..
Power loss calculations. (i) from power consumed by resistors :
Power = (0.71472 × 4) + (3.5722 × 2)+(2.8752 × 8) = 92.86 watts
(ii) From Source-power.
Power = 10 × 3.572 + 20 × 2.857 = 92.86 watts