thank you for all

 

No.

The equation will look something like this:

12 + (-10*I) + (-15*I) + (-5) + .... etc. = 0

It would be best to label your resistors R1, R2, etc.

Hence

12 - I*R1 - I*R2 - 5 + ... etc. = 0

thank you

 

Now show your work for the right hand side of the diagram.

 

The simple way using KVL is to add up all of the voltages correctly, considering the polarity of each. Then add up all of the resistances, and then calculate the current, which will be constant around a loop like this. Then caclulate the voltage across each resistor between a and b. Next, add the voltages correctly, using the polarity of each, as some will be piositive and other voltages will be negative. That will be the correct answer. NOW, to verify that it is correct, add the voltages between A and B using the other half of the loop, and it should be the same.
This is why it is vital to pay attention in class.