Use the Delta-Wye transformation to find the resistance as seen at  the inpu

Use the Delta-Wye transformation to find the resistance as seen at  the inpu 
Use the Delta-Wye transformation to find the resistance as seen at  the input. Label each Delta/Wye you identify on the circuit diagram and  discuss your approach and your reasoning for the solution.
Why do industrial plants use power factor correction? Here is a good resource to read. Find other examples and list your resources.