I have problem about circuit... I am trying to solve it, but It's too difficult to me..

somebody could help me. Plz T^T...

 

Hi,

Normally in the homework section we ask that you post your first attempt so we can see where you are in your studies, otherwise we might post advanced procedures that you dont understand or procedures that are too simplified for your course work, and also because we dont really do the entire homework for the person.

At least state where you got to so far with this
I can say you are lucky because the buck circuit is the simplest of them all.