The values of x and y vary directly and one pair of values are given. Write an equation that relates x and y. Simplify completely. x=-4,y=6 Please Help Me!!!

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