Show that the quadrilateral is a parallelogram for the given values of the variables. x = 3 y = 9

Oscar and julie ashton are celebrating their 15th anniversary by having a reception hall. they have budgeted $4,500 for their reception. if the reception hall charges a $90 cleanup fee plus & 36 per person, find the greatest number of people that they may invite and still stay within their budget.

Having a hard time understanding this question (see attachment).

Aline passes through the point (–7, 5) and has a slope of 1/2 which is another point that the line passes through?