Question

Can you help me with Data Using Matrices?
What is the sum of
https://www.connexus.com/content/media
/456845-3302011-105643-AM-1255958958.png

THANKS!

Answer 1

Can't access the link. Would it be possible to use the equation button or type out the matrices?

Answer 2

for sure

Answer 3

[3 -2] + [-5 -4]
[4 -3] [3 -2]

does that look familiar to you?

Answer 4

yes.

Answer 5

\[\left[\begin{matrix}3 & -2 \\4 & -3\end{matrix}\right] + \left[\begin{matrix}-5 & -4 \\ 3 & -2\end{matrix}\right]\]
This is the problem correct?

Answer 6

yes, perfect :)

Answer 7

Great. To add two matrices, all you need to do is add the number that are in the same spot. So 3 + (-5), -2 + (-4), etc.
You should end with another 2x2 matrix

Answer 8

Do i also do that for the bottom?

Answer 9

yup

Answer 10

okay so I came up with

[-2 -6]
[7 -5]

Answer 11

perfect.

Answer 12

thank you so much for your help!

Answer 13

no problem.

Answer 14

I have a question, what if the matrix below is equal to -6 ... how do I solve that? [2 -7] [-3 4]

Answer 15

[2 -7]
[-3 4]

Answer 16

Am i going to multiply the (-6) by the other numbers in the matrix?

Answer 17

hmmm... sorry this is taking so long, I'm a little fuzzy with some of the terminology and I was try to look it up.

Answer 18

no problem, I am doing the same ... what did you come up with?

Answer 19

Well, is it \[-6 \left[\begin{matrix}2 & -7 \\-3 & 4\end{matrix}\right]\] = -6
or is it \[-6\left[\begin{matrix}2 & -7 \\-3 & 4\end{matrix}\right]\]

Answer 20

If it's \[\left[\begin{matrix}2 & -7 \\-3 & 4\end{matrix}\right] = -6 \]
Then, I think, you want to find a 2x2 matrix that, when you add it to the first one, you get a mtrix with -6 in each spot.

Answer 21

yeah i did that and came up with
[-4 -13]
[-9 -2]

is that right?
All I did was add (-6) to the numbers in the matrix

Answer 22

Nope you need something that when added to the matrix gives an answer of -6

Answer 23

so \[\left[\begin{matrix}-8 & 1 \\ -3 & -10\end{matrix}\right]\]

Answer 24

yeah, that rights :)

Answer 25

\[\left[\begin{matrix}2 & -7 \\-3 & 4\end{matrix}\right] + \left[\begin{matrix}-8 & 1 \\ -3 & -10\end{matrix}\right]=\left[\begin{matrix}-6 & -6 \\ -6 & -6\end{matrix}\right]\]

Answer 26

oh! see, they tried to trick me with the wording haha

Answer 27

I think this is what they wanted, but I'm not a 100% sure. (Maybe 90%)

Answer 28

I think your right, it is the correct answer because it matched one of the multiple choices

Answer 29

ok, that's good.

Answer 30

can you help me define what do they mean by ...
What is the value of x in the equation 2?

if there are 3 matrices

Answer 31

2[-6 9] - [-4 -6] = [-8 x]
[-3 1] [-5 3] [-1 -1]

What is the value of x in the equation above?
I don't understand how can i solve it?

Answer 32

Multiple Choices
a. -24
b. -12
c. 12
b. 24

Answer 33

ok, so instead of having to worry about the entire matrix, we only have to look at the top right corner.

Answer 34

okay, so the one that includes an (x) right?

Answer 35

yup
that's what you need to find.

Answer 36

So, first, the 2 outside the first matrix means you need to multiply that matrix by 2 (normally you do all the numbers in the matrix, but in this case we're only worried about 1 number.) So, do that first.

Answer 37

so I am going to multiply 2 by what? Which number in the matrix?

Answer 38

Which number is in the spot we're looking at?

Answer 39

2x?

Answer 40

nope, you need to look at the numbers in the matrix the 2 is next to.

Answer 41

2[-6 9] - [-4 -6] = [-8 x]
[-3 1] [-5 3] [-1 -1]

so the 2 is next to [-6 9]
[-3 1]

Answer 42

but we are only concentration on the
[-8 x]
[-1 -1]

so i don't get it

Answer 43

yep, and which number ( -6, 9, -3, or 1) is in the same spot as the x?

Answer 44

ok got it, (9)

Answer 45

9x2= 18

Answer 46

yup.

Answer 47

ok, next we have subtraction. so, 18 - the number in the second matrix that's in the same spot as the x.

Answer 48

omg you are a lifesaver! THANK YOU SO MUCH FOR YOUR TIME AND ALL THE TROUBLE THAT I CAUSED YOU!

18 - (-6) = 24
Answer (D)

Answer 49

It's not a problem. I like helping people understand math better.

Answer 50

you sure do a great job ... Thanks :)

Answer 51

yup. :)