Question

Did I do this right?

x + y = 5
3x - y = -1

V=My answer is bellow=V

Answer 1

you mean did you set the matrix correctly?
then yes, you did!

Answer 2

Now you got to solve this, do you need help doing this?

Answer 3

yep you set it up correctly

Answer 4

let me extract an intext latex for matrix for you

Answer 5

```
\(\large\color{slate}{ \left[\begin{matrix}~1~ & ~1~ & |&~5 \\ ~3~ & ~-1~ & |&~-1
\end{matrix}\right] }\)
```

Answer 6

So, you have: (to see it inside) \(\large\color{slate}{ \left[\begin{matrix}~1~ & ~1~ & |&~5 \\ ~3~ & ~-1~ & |&~-1 \end{matrix}\right] }\)

Answer 7

I would multiply the first row, and add it to the second row.
(leaving your first row as it originally is, but changing the second row by doing this)

Answer 8

wow sorry my internet freaked out

Answer 9

i am just now seeing ur reaplys

Answer 10

you can take your time to process what I said, I hope I didn't say something outstandingly abstruse.

Answer 11

okay, now after you have: \(\large\color{slate}{ \left[\begin{matrix}~1~ & ~1~ & |&~5 \\ ~3~ & ~-1~ & |&~-1 \end{matrix}\right] }\)

you do this:

\(\large\color{slate}{ \left[\begin{matrix}~1~ & ~1~ & |&~5 \end{matrix}\right] }\) times -3,

you get: \(\large\color{slate}{ \left[\begin{matrix}~-3~ & ~-3 & |&~-15 \end{matrix}\right] }\)


add this to the second row:
\(\large\color{blue}{ \left[\begin{matrix} ~3~~~~~ & ~-1~~~ & |&~-1 \end{matrix}\right] }\)

\(\large\color{slate}{ \left[\begin{matrix}~-3~ & ~-3 & |&~-15 \end{matrix}\right] }\)

Answer 12

this addition gives you?
(this would be your new second row)

Answer 13

ok I was confused if I should replace the top x and y with 1 cuz it didn't say in my text book

Answer 14

no replacing, have you done elimination before?

Answer 15

like subtracting on normal equations from each other?

Answer 16

ya but forgot

Answer 17

okay, we have:

\(\large\color{slate}{ \left[\begin{matrix}~1~ & ~1~ & |&~5 \\ ~3~ & ~-1~ & |&~-1 \end{matrix}\right] }\)

lets multiply the first row times -3 what will this row be after this multiplication, can you tell me?

Answer 18

times 1 by -3?

Answer 19

everything in the row, each term, times -3.

Answer 20

k

Answer 21

you get?

Answer 22

1 x -3 = -3 and 5 x -3 = -15

Answer 23

yes, so the row will be:

\(\large\color{blue}{ [ ~~-3~ ~-3~ |~-15 ] }\)

Answer 24

ok

Answer 25

now, you are adding this to the second row:

\(\large\color{blue}{ ~~~~~~ [ ~~~~3~~~-1~~~ |~-1 ] }\)
\(\large\color{red}{ ^{^{\color{black}{\Huge+}}}~ [ ~~-3~ ~-3~ |~-15 ] }\)
\(\large\color{blue}{ ^{\color{black}{\text{____________________________}}}}\)

Answer 26

what will this addition give you?

Answer 27

so wait I add 3 to -3 and -1 to -3 and -1 to -15?

Answer 28

0, -4 and -16

Answer 29

yes you add it like this

Answer 30

yes, so your new matrix will look like: \(\large\color{slate}{ \left[\begin{matrix}~1~ & ~1~ & |&~5 \\ ~0~ & ~-4~ & |&~-16 \end{matrix}\right] }\)

Answer 31

@SolomonZelman , just wondering have you created a tutorial on matrices for us?

Answer 32

I don't create math tutorials too much time it willl take for me

Answer 33

I do some examples, and most of the stuff I am able to put up i "latex" it is here called.

Answer 34

pity @SolomonZelman

Answer 35

You can message me, I accept messages from people (besides the blocked individuals).
Don't do this in someone's question, please.

Answer 36

\(\large\color{slate}{ \left[\begin{matrix}~1~ & ~1~ & |&~5 \\ ~0~ & ~-4~ & |&~-16 \end{matrix}\right] }\) this is what we now have.


CAn you simplify the second row?

Answer 37

these are the answers thats not there

Answer 38

yes of course it is not

Answer 39

we are not done, lol

Answer 40

oh thats not all?

Answer 41

\(\large\color{slate}{ \left[\begin{matrix}~1~ & ~1~ & |&~5 \\ ~0~ & ~-4~ & |&~-16 \end{matrix}\right] }\) again, please simplify the second row for me

Answer 42

dang

Answer 43

add 0 to 1 and -4 to 1?

Answer 44

you are not adding to simplify the second row.

divide each term in the second row by -4.

Answer 45

ok sorry

Answer 46

can you divide each term in the second row by -4 ?

Answer 47

i am 0 + -4 = 0 and -4 + -4 is 1

Answer 48

sorry the + is /

Answer 49

typo

Answer 50

-16/-4 is 4

Answer 51

yes, so we have: \(\large\color{slate}{ \left[\begin{matrix}~1~ & ~1~ & |&~5 \\ ~0~ & ~1~ & |&~4 \end{matrix}\right] }\)

Answer 52

So we already got the y, now for x we need one compound step.

Answer 53

k

Answer 54

you are to multiply the 2nd row by -1.
add this second row to the first row.

Answer 55

what do you get after multiplying the second row times -1?

Answer 56

0 x -1 = 0, 1 x -1 = -1 and 4 x -1 is -4

Answer 57

yes,
[ 0 -1 | -4 ]

Answer 58

add this to the first row:

[1 1 | 5 ]
[0 -1 | -4]

Answer 59

what do you get after adding this?

Answer 60

1, 0 | 1

Answer 61

yes, so you have:

\(\large\color{red}{ \left[\begin{matrix}~1~ & ~0& |&~1 \\ ~0~ & ~1~ & |&~4 \end{matrix}\right] }\)

Answer 62

you are done:
x=1
y=4

Answer 63

I am in rush, bye

Answer 64

bye

Answer 65

thnx