A rabbit and a turtle run 100 meters. When the rabbit finished, the turtle was behind by 80 meters. Next time they want to finish together. The turtle still runs 100 meters. How many meters behind the turtle should the rabbit start? (Assume that they run at a constant rate during the competition.) ITS NOT 80

Afarmer has a large field that is x feet in length. he wants to fence in a rectangular section in the middle of the field , leaving a length of 100 feet of open field behind each end of the fenced rectangle.he also wants the width of the fenced-in space to be 100 feet less than its length. find the expressions to represent the length and width of the fenced section of the field