What is the opposite of 15/18 is

Working on itts i’m going to need you to me as i go along 1-5

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

1. writing an equation for an exponential function by 2. a piece of paper that is 0.6 millimeter thick is folded. write an equation for the thickness t of the paper in millimeters as a function of the number n of folds. the equation is t(n)= 3. enter an equation for the function that includes the points. (-2, 2/5) and (-1,2)