May someone help me with my AP calculus practice regarding "Optimization". we got off of school today for snow so we have to learn about it and do the lesson today at home and I'm confused on how to do these problems.

POS Find two numbers whose sum is 10 for which the sum of their squares is a minimum. The numbers are 5 and 5A farmer has 2,000 feet of fencing to enclose a pasture area. The field will be in the shape of a rectangle and will be placed against a river where there is no fencing needed. What is the largest area field that can be created and what are its dimensions? The dimensions of the area should be length = it and width = it with an area of sq feet.After winning a U.S. Open Tennis match at Arthur Ashe Stadium, players fire several tennis balls into the stands as souvenirs. Some players try to hit the ball out of the stadium, at a height of 518 feet. It has never been done. If the ball is propelled from a tennis racket straight up, the ball's height after t seconds is given by h = vot-16t where vo is the initial velocity. What is v. in order for the ball to reach a maximum height of 518 feet? How long will it take for the ball to reach that height? The ball will reach the maximum height at t = seconds. (Round answer to 3 decimal places)Find nonnegative numbers x and y whose sum is 75 and for which the value xy is as large as possible. The numbers are and