I need the answers because I really confused

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

To decrease an amount by 16% what single multiplier would you use

Abook store is having a 30 perscent off sale. diary of the wimpy kid books are now 6.30 dollars each what was the original price of the books