Which quadratic equation is equivalent?

How do you determine whether a relationship represented as as graph is linear or nonlinear

What is the perimeter of a rectangular building that is 80 feet wide and 140 feet deep?

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)