Here you go :) I sent the work in the picture below
Answer:
8. 
9. 
Step-by-step explanation:

^#8^

^#9^
Question 9 answer is 80 and for 10 it is 72 and for 11 it is 112 and for 12 it is 143
Answer:

Step-by-step explanation:
When finding the average of a set of numbers, we
- A) Add up all the numbers
- B) Divide that sum by the total number of numbers in the data set
Let's represent this with a formula, s being the sum of all numbers, n being the total number of numbers.

Since we <u>already know the sum</u> and we <u>know how many numbers there are</u> (8), we can substitute inside our expression
to find the average.
Therefore, the average of all these numbers is 11.25.
Hope this helped!
Answer:
Solution (-2, 7)
Step-by-step explanation:
2x + 3y = 17 (1)
5x + 6y = 32 (2)
Using elimination method
Multiply (-2) to the equation (1)
-4x - 6y = -34
Now you have 2 new equations
-4x - 6y = -34
5x + 6y = 32
----------------------------Add
x = -2
Substitute x = -2 into 2x + 3y = 17
2(-2) + 3y = 17
- 4 + 3y = 17
3y = 21
y = 7
Solution (-2, 7)