Delta-Wye Transformations: How to Simplify Complex Circuits for Easy Analysis

[GreatEscapist]

URGENT: Delta-Wye transformations

Hello there. In my electrical fundamentals class (a 201 level class), we just barely started Delta-Wye transformations. However, the homework that is due online tonight uses full transformations...confused, I have just tried to work through this using the book. I have become stuck...

My homework is due tonight at midnight, so please help asap?

Homework Statement

All attached

Homework Equations

Ohm's law, and...I don't know the other ones

The Attempt at a Solution

I have worked through most of the solution in the jpg. However, I am stuck. I know I need to find I, because if I can find I, it would be very simple to use Ohm's law in the original circuit.

I have tried to add the series and do parallel to leave

16.87 + 9.62 || 55.5 = Rd

then Rd || 36

Then you are left with a simple circuit to determine I, which I calculated to be 4.4A.

Can someone please help? haha

 

[GreatEscapist]

Sorry, didn't attach the first time

 

[gneill]

Check the value that you obtained for Ra from the Y-Δ transformation; either it's not correct or something went wrong with combining it with the 29Ω resistor. Then continue to reduce the network until you're left with two resistances forming a voltage divider.