How can I revise my essay for a better "flow" of ideas?

Having a good flow means that your essay can be easily read and understood by your reader. Two criteria need to be met in order to have a good "flow". That is, clarity and concision. A big, hindering factor for the first criterion could be your choice of words. You need to make sure that you adequatly choose your words and that they fit the context you are employing them in. Start from the premise that "there are no exact synonyms in English". For the second criterion, which is concision, you need to be able to reduce your sentences to their simplest forms. If your sentence contains too many clauses, it's probably not a good sign. After making sure that your essay is clear and concise, you are left with one last step; putting transitions between sentences.

Why is it that inflation rate and unemployment rate negatively correlated?

Let's say I live in a family where my dad decided to stay home to take care of my younger siblings. In this case, the family's sole source of income is my mom's full-time job. If my father judged that it is necessary to find a job and eventually started working. The family's disposable income suddenly increases significantly. This means that this particular family is now capable of affording larger basket of goods and services. At the level of the economy, the more people work, the more income they earn and the more money they spend. When the demand for products and services rises, pressure is put on the prices and they eventually rise. In other words, inflation increases.

How to distinguish between a purchase that should be capitalized or expensed?

Excellent question! It shows that you started to reason like an accountant. Here is a simple analogy you can build when confronted with such question. On the individual level (say yourself), you generally buy two category of products: one that is consumed quickly, and the other takes significantly more time to use or consume. An example of that would be a double cheese burger versus a computer. The same process happens at the firm's level. The firm buys things ranging from expensive machinery that last years to printers' cardriges (for instance) that last for few days. Purchases that can be used for more than 1 year are capitalized while those that are used less than a year are expensed.