Stuck with my reading. Pre School problem

I am continuing for last days and almost understand everything written here. First five section was easy and simple to understand.

I am loosing my mind with the sixth. I am good at math but getting confused with the theory and charts. Is there any other easy way or direct example that can clarify this to me?

Please, let me know. topics name is: Margin Trading 101: Understand How Your Margin Account Works

I can’t be sure what exactly is written in the Ch.6 , but try to go step by step through learning material. If you have specific question, post it here. In general, margin is sort of debt to your broker and if you are making loses your might get margin call, i.e. to return some funds to your account