Really confused

7. Define net exports. Explain how U.S. exports and imports affect domestic production. Explain how net exports can be negative. 8. In some country personal consumption expenditures in a specific year are $50 billion, purchases of stocks and bonds and $30 billion, net exports are -$10 billion, government purchases are $20 billion, sales of secondhand items are $8 billion, and gross investment is $25 billion. What is the GDP for this year