Question

If B [7 3 -2] find -3b
[5 4 3]
[ 21 9 -6]
[-15 -12 9]

[21 9 -6]
[15 12 9]

[10 6 1]
[8 7 6]

[4 0 -5]
[2 1 0 ]

Answer 1

multiply all elements of the matrix B, by -3

Answer 2

can you give me a example ? @UnkleRhaukus

Answer 3

\[\mathrm X
= \begin{bmatrix}-2&3\\7&8\end{bmatrix}\]

\[-5\mathrm X
= -5\begin{bmatrix}-2&3\\7&8\end{bmatrix}
=\begin{bmatrix}(-5\times-2)&(-5\times3)\\(-5\times7)&(-5\times8)\end{bmatrix}
=\begin{bmatrix}10&-15\\-35&-40\end{bmatrix}\]

Answer 4

understand?

Answer 5

Yes i see what you did there ? but am i doing that to the whole b because then ill end up with three columns instead of 2.

Answer 6

another example

\[\mathrm M
= \begin{bmatrix}-1&-2&-3\\2&3&0\end{bmatrix}\]

\[-4\mathrm M
= \begin{bmatrix}4&8&12\\-8&-12&0\end{bmatrix}\]

Answer 7

multiply every element of the matrix B, by -3

Answer 8

Ok so i got -21 -15 -9 -12 6 -9

Answer 9

B = [7, 3, -2;
5, 4, 3]


-3B = [(-3*7), (-3*3), (-3*-2);
(-3*5), (-3*4), (-3*3)]

= [-21, -9, 6;
-15, -12, -9]

Answer 10

...

Is there a typo in the question, or maybe the options?

Answer 11

it was a typo in the answers the answer is a. thank you. @UnkleRhaukus

Answer 12

cool, d'you understand it all now?

Answer 13

yeah after it was broken down. @UnkleRhaukus

Answer 14

Good \(\ddot\smile\)