Consider the following input tables and the query (with a placeholder line Determine the value of when we execute the query on these input tables after replacing the marked line__ ) by each of the following: Your answer should be an integer for each execution of the query. SELECT SUM(t_book.num_purchase) + SUM(t_other_num_purchase) AS num_purchase FROM ( SELECT user_id, num_purchase FROM ) AS t_book \# (SELECT user_id, num_purchase FROM t_other) AS t_other ON t_book_user_id = t_other_user_id