Why was the Louisiana Purchase regarded as one of the greatest real estate deals in history?

Which political reform gave people the power to put a proposed law on the ballot? referendum initiative direct primary recall

In the spring of 1989, thousands of protesters gathered in tiananmen square in beijing, china. they rallied around a plaster statue that resembled the statue of liberty which they called “the goddess of democracy.” these protestors were seeking a) united states assistance in gaining better health care. b) economic reforms which would allow more chinese exports. c) the boycott of the future olympic games scheduled for beijing. d) political reforms to allow more freedom of speech and political representation.

When recursive formula can be used to determine the total amount of money earned in any year based on the amount earned in the previous years?