Answer: a) AB = $\left[\begin{array}{ccc}-14&26\\-11&22\end{array}\right]$ ; b) $\left[\begin{array}{ccc}5&-5\\13&9\end{array}\right]$ ; c) No, they are different; d) No, they are never the same;

Step-by-step explanation:

a) A = $\left[\begin{array}{ccc}-2&4\\1&3\end{array}\right]$ , B = $\left[\begin{array}{ccc}-2&1\\-3&7\end{array}\right]$ . This multiplication is possible, because matrix A has 2 columns and matrix B has 2 rows. When those value are equal, the multiplication is possible.

AB = $\left[\begin{array}{ccc}-2&4\\1&3\end{array}\right]$ . $\left[\begin{array}{ccc}-2&1\\-3&7\end{array}\right]$ = $\left[\begin{array}{ccc}-14&26\\-11&22\end{array}\right]$

b) BA = $\left[\begin{array}{ccc}-2&1\\-3&7\end{array}\right]$ . $\left[\begin{array}{ccc}-2&4\\1&3\end{array}\right]$ = $\left[\begin{array}{ccc}5&-5\\13&9\end{array}\right]$

c) As, we can see, parts a and b are differents.

d) With matrices, multiplication is not commutative, which means AB≠BA

3 0

4 years ago

Read 2 more answers

1. Find the probability of rolling a sum less than 4 or a

-Dominant- [34]

<h3>Answer: 13/36</h3>

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Explanation:

Refer to the chart below. The values in red up top add to the values in blue along the left column to get the 6 by 6 grid of values inside. This represents all of the possible ways to add up values on a pair of dice. There are 6*6 = 36 outcomes.

Of those 36 outcomes, we have 13 outcomes where we roll less than a 4, or greater than 8

outcome = 1+1 = 2
outcome = 1+2 = 3
outcome = 2+1 = 3
outcome = 3+6 = 9
outcome = 4+5 = 9
outcome = 5+4 = 9
outcome = 6+3 = 9
outcome = 4+6 = 10
outcome = 5+5 = 10
outcome = 6+4 = 10
outcome = 5+6 = 11
outcome = 6+5 = 11
outcome = 6+6 = 12

These 13 results are shown in green boxes in the diagram.

Since we have 13 ways to get what we want, out of 36 total, the final answer as a fraction is therefore 13/36

13/36 = 0.3611 = 36.11% approximately

5 0

3 years ago