The Inca Empire was a vast empire that flourished in the Andean region of South America from the early 15th century, up until its conquest by the Spanish in the 1530s. They managed because they built their empire without wheel, powerful draft animals, iron working, currency or even what we would consider to be a writing system. To support this empire, a system of roads streteched for almost 25,000 miles , about three times the diameter of the Earth.
The Persian Wars gave the Greeks a new feeling of confidence. The Ionian Greek cities, once subject states to the Persian king, gained their independence. The Greek world would go on to achieve great things, led by the city-state of Athens.
A constant term in an expression is a term that does is independent of any variables. This means that constant term will have non of the variables attached to them. In the expression we notice that the terms integers 4 and 5 are the only terms that are not coefficients of any of the variables in the expression.
