Answer: Is true sometimes.
Step-by-step explanation:
I guess that here we have two matrices, A and B, that are nxn.
We can see that if those matrices can conmutate, then we can try it with some simple matrices.
![A = \left[\begin{array}{ccc}1&0\\0&-1\end{array}\right] . B = \left[\begin{array}{ccc}2&0\\1&1\end{array}\right]](https://tex.z-dn.net/?f=A%20%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1%260%5C%5C0%26-1%5Cend%7Barray%7D%5Cright%5D%20.%20B%20%3D%20%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D2%260%5C%5C1%261%5Cend%7Barray%7D%5Cright%5D)
Here, we would have that:
![AB = \left[\begin{array}{ccc}2&0\\-1&-1\end{array}\right]](https://tex.z-dn.net/?f=AB%20%3D%20%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D2%260%5C%5C-1%26-1%5Cend%7Barray%7D%5Cright%5D)
![BA = \left[\begin{array}{ccc}2&0\\1&-1\end{array}\right]](https://tex.z-dn.net/?f=BA%20%3D%20%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D2%260%5C%5C1%26-1%5Cend%7Barray%7D%5Cright%5D)
You can see that AB and BA are different, then the statement is not always true.
But it is true sometimes, if A or B are the identiti, then I*A = A*I, in this case would be true.
It is also true if A and B are diagonal matrices, let's prove it:
![A = \left[\begin{array}{ccc}a&0\\0&b\end{array}\right] , B = \left[\begin{array}{ccc}c&0\\0&d\end{array}\right]](https://tex.z-dn.net/?f=A%20%3D%20%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Da%260%5C%5C0%26b%5Cend%7Barray%7D%5Cright%5D%20%2C%20B%20%3D%20%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Dc%260%5C%5C0%26d%5Cend%7Barray%7D%5Cright%5D)
![AB = \left[\begin{array}{ccc}ac&0\\0&bd\end{array}\right] = BA](https://tex.z-dn.net/?f=AB%20%3D%20%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Dac%260%5C%5C0%26bd%5Cend%7Barray%7D%5Cright%5D%20%3D%20BA)
Answer:
-1.825
Step-by-step explanation:
Just subtract!
Answer:
1.61 * 10 ^8
3.3 * 10^-7
Step-by-step explanation:
Multiply the numbers and then add the exponents
2.3 * 10^1 * 7 * 10^6
2.3 *7 * 10^(1+6)
16.1 * 10^7
We need to make this scientific notation by moving the decimal one place to the left and adding 1 to the exponent
1.61 * 10 ^8
Multiply the numbers and then add the exponents
1.1* 10^-5 3*10^-2
1.1 *3 * 10^(-5+-2)
3.3 * 10^-7
(A) 1.18*10^3
When you multiply by 10^3, that means you're moving the decimal 3 places to the right.
1.18 becomes <em>1,180</em>.
(B) 6.701*10^-2
When you multiply by a negative exponent, it moves the decimal to the left. 10^-2 moves the decimal 2 places to the left.
6.701 becomes <em>0.0671</em>
