________ is the value of a good minus the price paid for it summed over the quantity bought

Which of the following explains why supply curves slope upward?

A) prices and income B) increasing marginal cost C) resources and technology D) substitutes in production and complements in production

The main components of spending, which can cause changes in aggregate demand, are: a. consumption, investment, government purchases, and net exports

b. consumption, investment, government purchases, and imports. c. investment, savings, replacement of depreciated equipment, and spending. d. consumption, savings, government purchases, and exports.