11x7/8 pls helpp i am so close from my test being over ty

Which best explains why this triangle is or is not a right triangle?

Tom wants to order tickets online so that he and three of his friends can go to a water park the cost of the tickets is 16.00 per person there is also a 2.50 one-time service fee for ordering tickets online write an expression in term of n that represents the cost for n ordering tickets online

Which value would be a solution for x in the inequality 47-4x< 7