![\left[\begin{array}{cc|c}-1&-1&-12\\-3&2&32\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7Cc%7D-1%26-1%26-12%5C%5C-3%262%2632%5Cend%7Barray%7D%5Cright%5D)
Multiply through row 1 by -1:
![\left[\begin{array}{cc|c}1&1&12\\-3&2&32\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7Cc%7D1%261%2612%5C%5C-3%262%2632%5Cend%7Barray%7D%5Cright%5D)
Add 3(row 1) to row 3:
![\left[\begin{array}{cc|c}1&1&12\\0&5&68\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7Cc%7D1%261%2612%5C%5C0%265%2668%5Cend%7Barray%7D%5Cright%5D)
Multiply through row 2 by 1/5:
![\left[\begin{array}{cc|c}1&1&12\\0&1&\frac{68}5\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7Cc%7D1%261%2612%5C%5C0%261%26%5Cfrac%7B68%7D5%5Cend%7Barray%7D%5Cright%5D)
Add -1(row 2) to row 1:
![\left[\begin{array}{cc|c}1&0&-\frac85\\&&\\0&1&\frac{68}5\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7Cc%7D1%260%26-%5Cfrac85%5C%5C%26%26%5C%5C0%261%26%5Cfrac%7B68%7D5%5Cend%7Barray%7D%5Cright%5D)
Answer: 6 and 9, 7 and 8. 69, 78, 87, 96. So, there are only 4 combinations which would result in 15.
Step-by-step explanation:
Therefore the average sum of three numbers is 45:3=15. The number 15 is called the magic number of the 3x3 square. You can also achieve 15, if you add the middle number 5 three times. The odd numbers 1,3,7, and 9 occur twice in the reductions, the even numbers 2,4,6,8 three times and the number 5 once.
It is approximately a thousand times larger
Answer:
ahem.........WOW
Step-by-step explanation: