It would be 7x-9 because 2x squared would be 4x, and you can only simplify two numbers if they have the same variable after it. So, all you can do is simplify this equation down to 7x-9.
So, at the beginning there are a total of 25*3=75 siblings (we can assume that each of them had exactly 3 siblings, that's what average means; that we can assume this).
Now we have 25+1=26 students and the number of siblings is 75+8=83
and the average is

, and rounded it's 3.19.
Answer:
are we supposed to find w ?
Step-by-step explanation:
i dk what to do, do you have a pic to go along?
5n = 40
n = 8 (Divide everything by five)
If you need further help just ask.