Answer:
Boys: 21.22 Girls: 16.89
Answer: A
Step-by-step explanation:
Add all the data points and divide it by the number of the data points.
Answer: 8n
Let's simplify step-by-step.
(2(n+1)−1)2−(2n−1)2
Distribute:
=4n2+4n+1+−4n2+4n+−1
Combine Like Terms:
=4n2+4n+1+−4n2+4n+−1
=(4n2+−4n2)+(4n+4n)+(1+−1)
=8n
9 is the answer for that problem
Hello, Here is a link to the answer. I am posting this link because it is a Brainly link and a verified answer
brainly.com/question/219158
The answer is 
Steps: (<em>in the attachment</em>)↓↓↓↓↓
<em>Hope this helps!!</em>
