Pls help it is easy math

Acomputer store bought a program at a cost of $10 and sold it for $13. find the percent markup

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)

Graph the equationy=x^2 -[tex]y = x^{2} - 2[/tex]