Alright so as far as I got it, I should chose a junction (in this case I chose A) and for that junction, only first closest capacitor in each branch that goes to that junction, his charge will be added into sumation with a sign thats turned to that junction,

and then I should write Voltage equations like this:

1. Choose a direction

2. Going through a loop, the sign of a voltage is the sign out of which the current from direction leaves.

So:

Q1 + Q3 = 0

E1 = Q2/C2 + Q1/C1

-E2 - E1 = - Q3/C3

And for U3 I got it correctly, its 36V.

for U2 and U1 values should be

U2 = 8 V

U1 = 4 V

but I got something else... So can someone please explain to me what mistakes am I making while writing equations either for charges

or voltages :/ ?