The answer to this question is y=5
Triangle angles add to 180 degrees. Thus, x - 17, x - 22, and 3x + 19 add to 180.
Add like terms to get 5x - 20 = 180
5x = 200
x = 40
The 9th student is in the middle.
⇒ There are 8 students before him
⇒ There are 8 students behind him
Total number of students = 8 + 1 + 8 = 17
Answer: 17
I’m sorry but I dont see anything