Question

2x+y=30
x+4z=20
2z+y=10
use row reduction; augmented matrices or whatever it's called o-o

@tutoriais

Answer 1

Are you sure this isn't a linear equation?

Answer 2

I can solve it using substitution

but i need to put it into the matrix thingy and then do it the matrix-y way

Answer 3

Oh, okay. give me a minute to draw this whole big thing out.

Answer 4

2x+30 isn't the answer. ._.

Answer 5

Okay, let's get this done.

Answer 6

i did nothing to make you call me dum i was trying to help you but no and I'm leaving I tried to help you but you don't want me to help you so I'm not helping you at all and can you help me pls and don't you say it I did not know that I got it wrong so sorry for getting it wrong you did not need to do that to me say sorry pls you are being mean I said what I said you did not need to say I don't any fractions so sorry I left you alone for a week so you can have some piece without me talk to you and I'm sorry I'm sorry and you don't have to see me ever

Answer 7

and

Answer 8

i dont know how to do

Answer 9

say it

Answer 10

My apologies, Snow. My Chromebook is sucking.

Answer 11

Okay, now...

Answer 12

lol, it's fine that happens often for me too

Answer 13

I have to wait until I get home, seems like this school wifi is quitting on me too much.

Answer 14

Sorry about that, snowflake. I'll be home in 20 minutes to answer your question.

Answer 15

mmm okay o-0

Answer 16

If you don't mind.

Answer 17

Never mind, seems to be working again.

Answer 18

noooo im sorry pls pls im sorry noooo pls an
ything but block and you did it so whyyou need help

Answer 19

X=1st Y=2nd Z=3

Answer 20

Would you like me to get down to the last one?

Answer 21

?_? just do whatever i'm supposed to do?

Answer 22

Okay, lol-

Answer 23

yeah lol ok so you no how to do abc cuzs this is ledders

Answer 24

yeah lol ok so you no how to do abc cuzs this is ledders

Answer 25

So, don't type anything-

Answer 26

me

Answer 27

No, the other person typing... ._.

Answer 28

\[2x+y=30\]
\[x+4z=20\]
\[2z+y=10\]
knowing that we can write:
\[ \color{lightskyblue}{\begin{bmatrix}2 & 1 & 0 &|30 \\ 1 &0& 4 &|20 \\ 0&1&2&|10 \end{bmatrix}} \]
from here we should put in work the row operations -- any ida?

Answer 29

no? i just know that i have to make a row have 2 0s

Answer 30

oh lord this will take ages to latex

apply \(new\ R_1=\frac{1}{2}R_1\) :
\[ \color{lightskyblue}{\begin{bmatrix}2 & 1 & 0 &|30 \\ 1 &0& 4 &|20 \\ 0&1&2&|10 \end{bmatrix}}
\Rightarrow\color{lightskyblue}{\begin{bmatrix}\frac{1}{2}2 & \frac{1}{2}1 & \frac{1}{2}0 &|\frac{1}{2}30 \\ 1 &0& 4 &|20 \\ 0&1&2&|10 \end{bmatrix}} \]
\[ \color{lightskyblue}{\begin{bmatrix}1 & \frac{1}{2} & 0 &|15 \\ 1 &0& 4 &|20 \\ 0&1&2&|10 \end{bmatrix}} \]

using that as an example, can you work \( new \ R_2=-1\times R_1+R_2 \) for the 2nd row?

Answer 31

how did you write it out like a matrix- how do i do that-

Answer 32

use the draw tool or https://sketch.io/sketchpad/?

Answer 33

actually before we do that, the NEXT step is going to be \( new \ R_2 -2 \times R_2 \)

do that first

then \( new\ R_1=-\frac{1}{2}R_2+R_1
\)

Answer 34

?_?
which row are we replacing with r2 - 2(r2)

Answer 35

oh r2

Answer 36

ok now do \( new\ R_1=-\frac{1}{2}R_2+R_1 \) and all of the other ones, untill you get to something which will look like

\[ \color{lightskyblue}{\begin{bmatrix}1 & 0 & 0 &|\#\\ 0 &1& 0 &|\#\\
0&0&1&|\#\end{bmatrix}} \]

the hashes will be respectively the solution

Answer 37

*clueless*

Answer 38

right, as discussed in dms, here is the list of every operation you will have to execute -- at this point just play around with it:
\[ new\ R_1=-\frac{1}{2}R_2+R_1 ​\]
\[ new \ R_3=-1\times R_2+R_3 \]
\[ new \ R=\frac{1}{10} R_3 \]
then

\[ R_1=-4 \times R_3+R_1 \]
\[ R_2=8 \times R_3+R_2 \]
and im pretty sure you will have an answer, exactly the same as we solve it last night in the form of a system.

Answer 39

thank youuuuuuuuuuuuuuuuuuuu