Does anyone know what 10.05-6.38 is?

Factor the monomial completely 42a3b3

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.

A25- foot ladder leans against a building and reaches a point of 23.5 feet above the ground .find the angle that the ladder makes with the building