QUICK plz. Don’t worry about the other questions just plz answer 17 for me :)

Awrestling tournament begins with 128 competitors. in the first round, each competitor has 1 match against another wrestler. the winner of each match moves on to the next round until there is a winner. write a sequence in which the terms represent the number of players still in the tournament at the end of each round. describe the sequence? how many rounds are in the tournament?

Which property was used to simplify the expression? 3c+9 +4c=3c+4c+9

What is the perimeter of an isosceles triangle with each leg measuring 2x+3 and the base measuring 6x-2?