Engineering Equivalent Single Load for Complex Delta and Y Connected Loads

[billyray]

Homework Statement

a) the equivalent single Δ-connected load
I have uploaded circuit

Homework Equations

none yet

The Attempt at a Solution

I am not sure if the question is asking me to find the resistance of both delta and y connected loads then work out them both in parallel. After I have the answer find a delta load for a circuit that equals this or simply find the delta loads impedance. That seems a bit easy from what i have done on my last question.
The questions after the question number a make me think i should do it the first way i said but i am a bit unsure.
also question b says i need to transform delta to y in question a but i don't see why.
Any advice please

 

[Baluncore]

Note that the loads are complex.
Approach load summation from the Δ side.
3a. Transform the Y load to a Δ, then sum the two parallel Δs into a single Δ load.
3b. Transform that parallel sum Δ from 3a, into a single Y load.
Now approach load summation from the Y side.
3c. Transform the Δ load of fig 3, to a Y, then sum it in parallel with the existing Y load to make one Y load.
3d. Find the real power dissipated in the complex Δ load.

also question b says i need to transform delta to y in question a but i don't see why.

So you can see that it does not matter how you approach the result. The Yb solution should be the same as the Yc solution.