How does one calculate a margin position’s liquidation price for Bitfinex and other exchanges?

I’m learning how margin works and wanted to understand how does liquidation price work in a margin position when using an exchange like Bitfinex? Their requirements is 30% equity.

Let’s say I deposited $ 1000 in USD and purchased $ 2000 worth of Bitcoin at the price of $ 1000 each BTC.

I understand that my equity is $ 1000 which is what I deposited.

What is my liquidation price and how does one calculate it?

And what other factors do I need to know when if I wanted to hold onto this margin position for many months?

Is it possible to get top positions without link-building?

Hello. My theme is biathlon (sport). And i'd like to create site about it on english.
There are easy rivalry (official site, and several news-sites).
But I haven't money for link building, it's risk. Can invest $ 100-200 :)

And i thinking, is it possible?

Last time i was on english section SEO … 8 years ago)) Then a lot of people used directories for boost.

What is now effectively?