A fence is to be built to enclose a rectangular area of 450 square feet. The fence along three sides is to be made of a material that costs $3 per foot. The material for the fourth side costs $9 per foot. Find the dimensions of the rectangle that will allow for the most economical fence to be built.

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)