I need help with applied geomatry

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.

Find the maximum value of p= 4x + 5y subject to the following constraints :

The triangles are similar. what is the value of x? enter your answer in the box.