Techwiz electronics makes a profit of $35 for each mp3 player sold and $18 for each dvd player sold. last week, techwiz sold a combined total of 129 mp3 and dvd players. let x be the number of mp3 players techwiz sold last week. write an expression for the combined total profit (in dollars) techwiz made from mp3 and dvd players last week.

The business cycle is the periodic but irregular up-and-down movement in economic activity, measured by fluctuations in real gross domestic product (gdp) and other macroeconomic variables. a business cycle is typically characterized by four phases—recession, recovery, growth, and decline—that repeat themselves over time. economists note, however, that complete business cycles vary in length. the duration of business cycles can be anywhere from about two to twelve years, with most cycles averaging six years in length. some business analysts use the business cycle model and terminology to study and explain fluctuations in business inventory and other individual elements of corporate operations. but the term "business cycle" is still primarily associated with larger (industry-wide, regional, national, or even international) business trends.