Don't understand how to do this, show steps

Aperpendicular bisector, cd is drawn through point con ab if the coordinates of point a are (-3, 2) and the coordinates of point b are (7,6), the x-intercept of cd is point lies on cd.

Is a positive integer raised to a negative power always positive

1) you deposit $2,500 in an account that earns 4% simple interest. how much do you earn in eight years?