I need help with these 2.

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

Consider the sequence below. 3 , 1 , 1/3 , 1/9 , select the explicit function which defines the sequence.

Astudent showed the steps below while solving the inequality |x-4|< 1 by graphing.