Help with what u can thx peeps brainliest :)

What is the value of x? enter your answer in the box. (cm)

The sum of two numbers is 86, and their difference is 20. find the two numbers

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.