I have a lot of problems to understand
That's my first class concerning managerial accounting

And I need seomeone help me

As I was trying to make a point of in your other post, long problems are difficult to do on here unless you at least halfway understand it, can get part of it done yourself, and just need some guidance on the rest. Managerial problems can be very long and involved. (Not all, certainly, but a lot of them.)

To do it on a forum like this, we would have to have some starting point, see if you understand that first, move on to the next point, etc. That would take a lot of posts back and forth. That can be done, but since we're all volunteers and come here around our real lives, there's no guarantees about how quickly you'll get the next question answered and that sort of thing. I'm here a lot and I'm willing to answer what I can, but it may have to come in bits and pieces. Something like your other problem would have to be worked in pieces. You'll also have to keep in mind that we aren't here to just do work for you -- so you need to try what you can and then get some guidance on the next step.

Or were you looking for a way to pay someone to work with you privately? Being online does create more difficulties from that point of view.