I don't think there's any need to start a new thread dealing with this same problem. It will just cause confusion as people end up posting to one, the other, or both threads. Let's keep it all in one place, okay?

okay i wont do that, thank you Wbahn, here i tried to make my work more clear
Frequency = 1000 Hz
Z1 = 69j ohms: Inductor
Z2 = 37 ohms: Resistor
Z3 = -111j ohms: Capacitor
Z4 = 119 ohms: Resistor
Z5 = Load impedance
Vs = 78 + j270 V
Vx = 4+ j140 V
i started by using a delta-wye transformation and i got this (i attached a pic that i used to do the transformation) :
Za =(Z1*Z2)/(Z1+Z2+Z3)=-34.22+j30.15 ohms
Zb =(Z2*Z3)/(Z1+Z2+Z3)=55.05-j48.50 ohms
Zc =(Z1*Z3)/(Z1+Z2+Z3)=90.45+102.67 ohms
then i wen to take Z5 which is the load then to find the total current i did
it =(Vs-Vx)/(Za+Zc+Z4)
Vza= -it*za
Vzc= -it*zc
Vz4= it*z4
so Eth = Vs+Vza or Eth= -Vzc+Vz4+Vx so if you would like to check my work and see if what i did is correct I would really appreciate it. Thank you.

 

The only thing new to check is your delta-wye transformation and it looks just fine. I didn't check Zb since that doesn't come into play for Vth and since you don't seem to be interested in Req for this particular problem.

 

The only thing new to check is your delta-wye transformation and it looks just fine. I didn't check Zb since that doesn't come into play for Vth and since you don't seem to be interested in Req for this particular problem.

i was able to get Req i have no problem with that, i jst want to know how to get Vth, so my Vth is correct right, the thing i have the straight answers to the problem but when i calculate Vth i cant seem to get match answers.

 

i was able to get Req i have no problem with that, i jst want to know how to get Vth, so my Vth is correct right, the thing i have the straight answers to the problem but when i calculate Vth i cant seem to get match answers.

Well, you haven't shown any calculation of Vth or what the answer is that you have been given as being the correct answer, so until you do that I can't really go any further.

 

Well, you haven't shown any calculation of Vth or what the answer is that you have been given as being the correct answer, so until you do that I can't really go any further.

this is the answer i am getting for Vth:
Vth = Vs+Vza = -Vzc+z4+Vx = 107.43+j260.27 V
and the answer that's given a being the correct answer is:
Vth = 122.99+j29.00 V

 

this is the answer i am getting for Vth:
Vth = Vs+Vza = -Vzc+z4+Vx = 107.43+j260.27 V
and the answer that's given a being the correct answer is:
Vth = 122.99+j29.00 V

This is somewhat like pulling teeth.

"Show your work" means more than just giving final answers.

What did you get for:

it = (Vs-Vx)/(Za+Zc+Z4) = ??? -- and show what you got for (Vs-Vx) and what you got for (Za+Zc+Z4).

Vza= -it*za = ???
Vzc= -it*zc = ???
Vz4= it*z4 = ???

Remember, you are asking strangers for help. If all you give is

Vth = Vs+Vza = -Vzc+z4+Vx = 107.43+j260.27 V

Then all we can respond is either yes or no. And that's after going through and doing all the math ourselves. Yet, after doing all that math, we can only say yes or no and we can't give you any feedback on where you went wrong (assuming you did). That's not much fun for us and, thus, not much incentive to put in the effort. But if you present your work so that we can follow through it step by step, we can then tell you what mistake you make in which step. That's a LOT more enjoyable for us and, thus, a great incentive for us to make the effort.

Bottom line, when asking for free help, make it easy for people to help you.

 

This is somewhat like pulling teeth.

"Show your work" means more than just giving final answers.

What did you get for:

it = (Vs-Vx)/(Za+Zc+Z4) = ??? -- and show what you got for (Vs-Vx) and what you got for (Za+Zc+Z4).

Vza= -it*za = ???
Vzc= -it*zc = ???
Vz4= it*z4 = ???

Remember, you are asking strangers for help. If all you give is

Vth = Vs+Vza = -Vzc+z4+Vx = 107.43+j260.27 V

Then all we can respond is either yes or no. And that's after going through and doing all the math ourselves. Yet, after doing all that math, we can only say yes or no and we can't give you any feedback on where you went wrong (assuming you did). That's not much fun for us and, thus, not much incentive to put in the effort. But if you present your work so that we can follow through it step by step, we can then tell you what mistake you make in which step. That's a LOT more enjoyable for us and, thus, a great incentive for us to make the effort.

Bottom line, when asking for free help, make it easy for people to help you.

Given values:
F = 1000 Hz
Z1 = 69i ohms
Z2 = 37 ohms
Z3 = -111i ohms
Z4 = 119 ohms
Vs = 78.00 + 270.00i V
Vx = 4.00 + 140.00i V
W = 2*pi*F

Delta-Wye Transformation

Za =(Z1*Z2)/(Z1+Z2+Z3) = (69i*37)/(69i+37-111i) = -34.22+30.15i ohms
Zb =(Z2*Z3)/(Z1+Z2+Z3) = (37*-111i)/(69i+37-111i)= 55.05-48.50i ohms
Zc =(Z1*Z3)/(Z1+Z2+Z3) = (69i*-111i)/(69i+37-111i)= 90.45+102.67i ohms

Calculating the equivalent Thevenin Voltage

Zt=Za+Zc+Z4 = -34.22+30.15i+90.45+102.67i+119 ohms = 175.23+132.82i ohms

It = (Vs-Vx)/Zt = (78 + 270i-4+ 140i)/ (175.23+132.82i) = (74+410i)/ (175.23+132.82i)
It = 1.39+1.28i A

Vza = -It*Za = - (1.39+1.28i A)*(-34.22+30.15i) = 86.15 + 1.89i V
Vzc = -It*Zc = - (1.39+1.28i A)*(55.05-48.50i) = -138.60 - 3.04i V
Vz4 = It*Z4 = (1.39+1.28i A)*(90.45+102.67i) = -5.69 + 258.48i V

Eth = Vs + Vza = (78 + 270i) + (86.15+ 1.89i) = 164.15+ 271.89i V

Eth2 = Vx+Vz4-Vzc = 4+ 140i+ (-5.69+ 258.48i)-(-138.60- 3.04i) = 136.91+401.52i V

Eth ≠ Eth2 this is what I came up with after doing all the calculations, apparently Eth = Vs + Vza doesn’t equal Eth2 = Vx+Vz4-Vzc. So please if you can go over my calculation, it would be great.I really appreciate you taking the time to help me with this, thank you very much.

 

It = (Vs-Vx)/Zt = (78 + 270i-(4+ 140i))/ (175.23+132.82i)

You need parentheses around the value of Vx; see the red color above. Redo the subsequent calculations.

 

You need parentheses around the value of Vx; see the red color above. Redo the subsequent calculations.

ok i redid the subsequent calculations
It = (Vs-Vx)/Zt = (78 + 270i-(4+ 140i))/ (175.23+132.82i) = (74+130i)/ (175.23+132.82i)
It = 0.62+ 0.26i A

Vza = -It*Za = - (0.62+ 0.26iA)*(-34.22+30.15i) = 29.05- 9.79i V
Vzc = -It*Zc = - (0.62+ 0.26iA)*(55.05-48.50i) = -46.74+ 15.75i V
Vz4 = It*Z4 = (0.62+ 0.26iA)*(90.45+102.67i) = 29.38+ 87.17i V

Eth = Vs + Vza = (78 + 270i) + (29.05- 9.79i) = 107.05+ 260.21i V

Eth2 = Vx+Vz4-Vzc = 4+ 140i+ (29.38+ 87.17i) - (-46.74+ 15.75i) = 80.12+ 211.42i V
i still get Eth not equal to Eth2, what am i doing wrong?

 

Check to see if you are satisfying KVL by summing everything up around the entire loop, being sure to take into account the polarities you assigned everything, and see if the total adds to zero.

 

ok i redid the subsequent calculations
It = (Vs-Vx)/Zt = (78 + 270i-(4+ 140i))/ (175.23+132.82i) = (74+130i)/ (175.23+132.82i)
It = 0.62+ 0.26i A

Vza = -It*Za = - (0.62+ 0.26iA)*(-34.22+30.15i) = 29.05- 9.79i V
Vzc = -It*Zc = - (0.62+ 0.26iA)*(55.05-48.50i) = -46.74+ 15.75i V
Vz4 = It*Z4 = (0.62+ 0.26iA)*(90.45+102.67i) = 29.38+ 87.17i V

Eth = Vs + Vza = (78 + 270i) + (29.05- 9.79i) = 107.05+ 260.21i V

Eth2 = Vx+Vz4-Vzc = 4+ 140i+ (29.38+ 87.17i) - (-46.74+ 15.75i) = 80.12+ 211.42i V
i still get Eth not equal to Eth2, what am i doing wrong?

You have a couple of errors; you should have:

Vzc = -It*Zc = - (0.62+ 0.26iA)*(90.45+102.67i) = ???
Vz4 = It*Z4 = (0.62+ 0.26iA)*(119) = ???

You probably should carry a couple of additional digits in your numerical calculations.

 

I agree.

As a good rule:

1) Final answers should be reported to three or perhaps four sig figs.
2) Intermediate results should have at least one and preferably two additional sig figs.

 

You have a couple of errors; you should have:

Vzc = -It*Zc = - (0.62+ 0.26iA)*(90.45+102.67i) = ???
Vz4 = It*Z4 = (0.62+ 0.26iA)*(119) = ???

You probably should carry a couple of additional digits in your numerical calculations.

thank you for pointing that out, I redid the calculations and this what i got
Zt=Za+Zc+Z4 = -34.22+30.15i+90.45+102.67i+119 ohms = 175.23+132.82i ohms

It = (Vs-Vx)/Zt = (78 + 270i-(4+ 140i))/ (175.23+132.82i) = (74+130i)/ (175.23+132.82i)
It = 0.625350+ 0.267882i A

Vza = -It*Za = - (0.625350+ 0.267882i A)*(-34.22+30.15i) = 29.4761- 9.68738i V
Vzc = -It*Zc = - (0.625350+ 0.267882i A)*(90.45+102.67i) = -29.0595- 88.4346i V
Vz4 = It*Z4 = (0.625350+ 0.267882i A)*(119) = 74.4166+ 31.8780i V

Eth = Vs + Vza = (78 + 270i) +(29.4761- 9.68738i) = 107.4761+ 260.3126i V

Eth2 = Vx+Vz4-Vzc = 4+ 140i+ (74.4166+ 31.8780i) -(-29.0595- 88.4346i)= 107.476+ 260.313i V

so I end up with Eth = Vs+Vza = Vx+Vz4-Vzc, it satisfies sum of KVL = 0
is my Eth correct now? thank you guys for your time

 

You have got the correct result, but as WBahn and I said, you should consistently carry more digits than you report in your final answer. In some calculations you only have 4 digits, and yet you have 6 digits in your final answer. You should carry 6 digits in all your intermediate calculations, but only give 3 or 4 digits in your final result.