Explanation:

The expenditure method is a system for calculating gross domestic product (GDP) that combines consumption, investment, government spending, and net exports. It is the most common way to estimate GDP.

It says everything that the private sector, including consumers and private firms, and government spend within the borders of a particular country, must add up to the total value of all finished goods and services produced over a certain period of time. This method produces nominal GDP, which must then be adjusted for inflation to result in the real GDP.