I need this question now please

Witch represents the inverse of the function f(x)=1/4x-12

Xy x xy if a and b are positive integers such that a*b=9 and b*a=72 what is the value of a/b

Technicians have installed a center pivot, circular irrigator for a farm that covers 25 acres. a.) how long is the irrigation boom (in feet) from the center pivot to its farthest extent? b.) if the irrigation boom makes 4 full revolutions in a day, how many miles does the end of the boom travel in 5 days?