This text provides solutions to various queries related to database systems. It covers details of employees, invoices, products, vendors and more. The queries include showing details of employees in a particular area code, sums of line units for each invoice, details of products without a value for the attribute v_code, details of invoices with subtotal greater than 25 but less than 75, details of invoice with minimum subtotal, details of products with line price greater than 100, purchases by customer 10011, codes and names of vendors who supplied products, codes of vendors and the number of products each vendor has supplied, codes of vendors who did not supply any products, and names and codes of vendors and the number of products each vendor has supplied.