I need to calculate the voltage at node A at the below circuit. Please tell me whether my approach is right

So, I am assuming that the 1000ohms in series with the voltage sources as internal resistances.

Current through the 500ohm would be, I = 10/500 = 20mA

But we need to consider the internal resistance of 1000ohms right

So, terminal voltage, Er = V - IR, Er = 10 - (20mA)*(1000Ohms) = 10-20 = -10V ?

What am i doing wrong here?

Please let me know