Step-by-step explanation:
5×a×5×a
collect like terms
5×5×a×a
25×a^2
25a^2
Answer:
See explanation
Step-by-step explanation:
Given:
![A=\left[\begin{array}{cc}-2&4\\1&3\end{array}\right]](https://tex.z-dn.net/?f=A%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D-2%264%5C%5C1%263%5Cend%7Barray%7D%5Cright%5D)
![B=\left[\begin{array}{cc}-2&1\\3&7\end{array}\right]](https://tex.z-dn.net/?f=B%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D-2%261%5C%5C3%267%5Cend%7Barray%7D%5Cright%5D)
A. Find AB:
![AB=\left[\begin{array}{cc}-2&4\\1&3\end{array}\right]\cdot \left[\begin{array}{cc}-2&1\\3&7\end{array}\right]=\left[\begin{array}{cc}-2\cdot (-2)+4\cdot 3&-2\cdot 1+4\cdot 7\\1\cdot (-2)+3\cdot 3&1\cdot 1+3\cdot 7\end{array}\right]=\left[\begin{array}{cc}16&26\\7&22\end{array}\right]](https://tex.z-dn.net/?f=AB%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D-2%264%5C%5C1%263%5Cend%7Barray%7D%5Cright%5D%5Ccdot%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D-2%261%5C%5C3%267%5Cend%7Barray%7D%5Cright%5D%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D-2%5Ccdot%20%28-2%29%2B4%5Ccdot%203%26-2%5Ccdot%201%2B4%5Ccdot%207%5C%5C1%5Ccdot%20%28-2%29%2B3%5Ccdot%203%261%5Ccdot%201%2B3%5Ccdot%207%5Cend%7Barray%7D%5Cright%5D%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D16%2626%5C%5C7%2622%5Cend%7Barray%7D%5Cright%5D)
B. Find BA:
![BA=\left[\begin{array}{cc}-2&1\\3&7\end{array}\right]\cdot \left[\begin{array}{cc}-2&4\\1&3\end{array}\right]=\left[\begin{array}{cc}-2\cdot (-2)+1\cdot 1&-2\cdot 4+1\cdot 3\\3\cdot (-2)+7\cdot 1&3\cdot 4+7\cdot 3\end{array}\right]=\left[\begin{array}{cc}5&-5\\1&33\end{array}\right]](https://tex.z-dn.net/?f=BA%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D-2%261%5C%5C3%267%5Cend%7Barray%7D%5Cright%5D%5Ccdot%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D-2%264%5C%5C1%263%5Cend%7Barray%7D%5Cright%5D%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D-2%5Ccdot%20%28-2%29%2B1%5Ccdot%201%26-2%5Ccdot%204%2B1%5Ccdot%203%5C%5C3%5Ccdot%20%28-2%29%2B7%5Ccdot%201%263%5Ccdot%204%2B7%5Ccdot%203%5Cend%7Barray%7D%5Cright%5D%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D5%26-5%5C%5C1%2633%5Cend%7Barray%7D%5Cright%5D)
C. Answers are not the same
D. Matrices multiplication is not commutastive in general, so

The area is 144. Because if it’s a square all sides are equal
12) Im not sure about this one
13) c
14)a
The volume is 1733.33 v = lwh /3
The surface area is 1056.05