The Science Club went on a two-day field trip. The first day the members paid $30 for transportation plus $12 per ticket to the
planetarium. The second day they paid $90 for transportation plus $9 per ticket to the geology museum. Write an expression to represent the total cost in dollars for two days for the n members of the club.
Focus of a Parabola. A parabola is set of all points in a plane which are an equal distance away from a given point and given line. The point is called the focus of the parabola and the line is called the directrix. The focus lies on the axis of symmetry of the parabola.
