The first image is the exercise the second image is what i have done can someone explain me what is my mistake? And is there a simpler way to do it?

No you are doing this wrong. You need to start at the end with R5 and R6 and work backwards to find total resistance for the circuit. Once you have that you can figure total current for the circuit. Once you have current you can work forwards and on your parallel and series circuits to calculate power. -Robert

Do what? I see no definitive statement from you about what you want to do. Is it "A", "B", "C", "D", or all the above? Why not submit the image in landscape format instead of portrait format so we can view the problem without lying down and avoid the truncation of "A" ? Ratch

That will work, but it is the hard way to do it. A easier and quicker way is to use node analysis to find the voltages at the R1-R3 node and the R3-R5 node. Two equations and two unknowns. Once those two voltages are known, then anything else can be easily calculated. Ratch

Another way to do it, thats kinda still a bitch to do... Is to just draw each loop from the battery separately, and then complete the resistance calc of each loop, then add them up to get your amps - for all locations on the circuit. (where the loops overlap, you have to count all loops go over that line.) Thats almost it, except you have to take into account load hogging when the loops come apart from each other.