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

Compute z-score. Given ~ n(12,2.5),find z score when x =17

Anestetic [448]

Answer:

The desired z-score is 2.

Step-by-step explanation:

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the z-score of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

n(12,2.5)

This means that $\mu = 12, \sigma = 2.5$

z score when x =17

This is Z when X = 17. So

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{17 - 12}{2.5}$

$Z = 2$

The desired z-score is 2.

3 0

3 years ago

Binomio al cubo <br> (x+2)3

vladimir2022 [97]

Answer:

3x+6

Step-by-step explanation:

(x+2)3

3(x)+3(2)

3x+6

8 0

3 years ago