Answer:
A
Step-by-step explanation:
Okay! You’re a girl right? Lol
Answer:
21
Step-by-step explanation:
Okay so since we have $389.42 to start with, we will multiply that by 3.2% which gives us roughly $12.46. Knowing that he will get an additional $12.46 per year, we multiply 12.46 by 7, giving us $87.22. Now, we just add 87.22 to 389.42, which is 476.64. Therefore, Armand has $476.64 as his account after 7 years.
Answer:
![\left[\begin{array}{cccc}1&0&1&|-1\\-3&-9&3&|27\\3&2&0&|-2\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcccc%7D1%260%261%26%7C-1%5C%5C-3%26-9%263%26%7C27%5C%5C3%262%260%26%7C-2%5Cend%7Barray%7D%5Cright%5D)
Step-by-step explanation:
Given [Missing from the question]
![\left[\begin{array}{cccc}1&0&1&|-1\\1&3&-1&|-9\\3&2&0&|-2\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcccc%7D1%260%261%26%7C-1%5C%5C1%263%26-1%26%7C-9%5C%5C3%262%260%26%7C-2%5Cend%7Barray%7D%5Cright%5D)
Required

This implies that, we form a new matrix where the second row of the new matrix is a product of -3 and the second row of the previous matrix.
So, we have:
![Initial =\left[\begin{array}{cccc}1&0&1&|-1\\1&3&-1&|-9\\3&2&0&|-2\end{array}\right]](https://tex.z-dn.net/?f=Initial%20%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bcccc%7D1%260%261%26%7C-1%5C%5C1%263%26-1%26%7C-9%5C%5C3%262%260%26%7C-2%5Cend%7Barray%7D%5Cright%5D)
![New =\left[\begin{array}{cccc}1&0&1&|-1\\-3*1&-3*3&-3*-1&|-3*-9\\3&2&0&|-2\end{array}\right]](https://tex.z-dn.net/?f=New%20%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bcccc%7D1%260%261%26%7C-1%5C%5C-3%2A1%26-3%2A3%26-3%2A-1%26%7C-3%2A-9%5C%5C3%262%260%26%7C-2%5Cend%7Barray%7D%5Cright%5D)
![New =\left[\begin{array}{cccc}1&0&1&|-1\\-3&-9&3&|27\\3&2&0&|-2\end{array}\right]](https://tex.z-dn.net/?f=New%20%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bcccc%7D1%260%261%26%7C-1%5C%5C-3%26-9%263%26%7C27%5C%5C3%262%260%26%7C-2%5Cend%7Barray%7D%5Cright%5D)