Question

R1=2 Ом R2=3 Ом R3=6 Om R4=5 Om A-? U-?

Answer 1

Если соединение последовательное сложите R1+...R4  найдите ток и работу:
I=U/Ro
A=UIt

Answer 2

I'm sorry, but your question is incomplete.

It appears that you have provided the values of four resistors (R1, R2, R3, R4), but you have not specified what you are trying to find.

Can you please provide more information about what you are looking for? For example, are you trying to find the equivalent resistance of a circuit containing these resistors, or are you trying to calculate the voltage or current at a specific point in the circuit?

Once I have more information, I can help you with your question.