I need with this math question pleasee

Find the magnitude of the torque about p if an f = 80-lb force is applied as shown. (round your answer to the nearest whole number.) ft-lb

A50% increase followed by 33 1/2% decrease

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