Hich function has a vertex at the origin?

f(x) = (x + 4)2
f(x) = x(x – 4)
f(x) = (x – 4)(x + 4)
f(x) = –x2

And employees salary increase by $4500 which represents a 15% raise what is the employees new salary

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)

Abox holds 500 paperclips. after a week on the teacher's desk 239 paperclips remained. how many paperclips were used?