Solving systems of equations by elimination | Algebra Basics | Khan Academy
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- เผยแพร่เมื่อ 7 เม.ย. 2010
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Solving Systems of Equations by Elimination. Created by Sal Khan.
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Algebra basics on Khan Academy: Topics covered in a traditional college level introductory macroeconomics course
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Anyone else feels like they can actually get to like math if only they can understand it?
Golden1 yes, once I leave it :)
Yep.
yup
yeah...
it is
Is anybody just not gonna talk about this guy's right to be one of the best teachers out there? He actually explains it in a way that makes sense.
yessir
Yess really good and simplified
"blah blah blah blah blah and don't forget to blahhhh~ blahh blah blah *You're gonna fail your test on friday* blah blah and blah" Is all I heard.
Cookies4monstas .....LOL
Cookies4monstas 🤣🤣🤣🤣
yes
Cookies4monstas I have a test on Friday on this 😂
Ava Brooks I went alright! Was a while ago, but like ten minutes before the test, the whole concept just instantly clicked
IRL They tell you the cost of the candy bar lmao
Ikr I really hate math
I was gonna say something smart but then I realized high school geometry is what that’s used for so nvm algebra is still pretty cancer
@@imswiiftz730 samee
@@imswiiftz730 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
I have my exam tomorrow and i still dont know how to do anything
bailey brown The most relatable thing I have seen all night
SAAMEEE
ayy same
bailey brown same
relatable
You know most teachers go in teaching this but don't explain how come we can add two equations. And you have this constant question in your mind. Well you have answered that question. Thank You!
Nazariy Dumanskyy
I can always get how, but rarely get why… these TH-cam videos help me with that
I don’t understand why this must exist. Why do we have to know elimination? Why can’t we just learn substitution, because apparently you will still have to use substitution if you do elimination. This learning system is RIGGED!
holy frack It sets you up for doing gaussian elimination, which is something else in linear algebra.
This process is faster than substitution. The only reason we do substitution is because elimination is situational. Also if you are going to talk about an easier method at least use graphing as an example.
relax, this will help you develop skills and think faster
My teacher should just show us your videos during class, I'd learn so much more in so little time. You've changed the world Sal!
Better than my boring teacher
so the reality hasn't changed even after 7 years :(
GOD DANG IT... He's so Organised in his videos! He is mote organised than ANY TEACHER I HAVE EVER SEEN plus he is using his mouse to write instead of Paper and Pencil. This guy explains stuff in detail VS. my Teacher who teaches methods with no explanations. My teacher taught this lesson without ever explaining WHY she is doing it! Khan Accademy... it has changed MILLIONS OF LIVES by teaching without price. This man is pure Genius! Please like this comment if you agree... 😔👹😔
SkillUp Gaming, it is good that you actually see that this video is good. Look at everyone dissing this video and you must wonder if they have a shred of intelligence.
Pray th3 superiority Indians
he actually has a pen where he can write on his tablet.
@@allen148 yeah, because writing all that with a mouse would be super hard, and hurt your hand a lot
There’s something called a tablet
"Fruit ROOLLL-UPP" @6:50 makes me lmao
Michael G I'll
HELP!! I TOOK HIS ADVICE AND NOW I'M STUCK IN AN INFINITE LOOP OF ADDING AND SUBTRACTING 1Y!!!!!!!!
legend has it that to this day, they're still in an infinite loop
@@doylejohnson7909 yo. I completely forgot about this comment lmao
@@James-mc7ws you still here?
@@Yes-zt1wq yep. I got out of the loop to cutting my arm off
@@James-mc7ws lol
This guy is a legend
no period
I LOVE YOU ADAN PB
When he said 2.5, I know that I’m going to fail my Math class
2.5 is equal to 2 + 0.5 and 0.5 is equal to half of 1
from 0:00 i knew im failing
Why??????
@@jerfersonmatos28 we know that
"Hey Sal, but wait..." You're the best, dude.
This is so complicated....and I still don't get it
i dont get it to like wtf i dont like khan academy everyone be boosting this guuy
its because your not old enought to understand scrub,
nyght lmao
Bill Hable
its as simple as it gets
I have a test tomorrow morning and I don’t understand any of this so please wish me good luck 😔😂🙇🏽♀️
did you do good
did u pass-
RIP ITS BEEN A YEAR
@@coast1501 yep
Oh god they failed so hard they died
It’s crazy I feel when people explain math! I feel they skip why they are doing certain things to the problems, they just write things in as if you know why they are doing the steps! I feel a great math teacher explains in detail why her or she is writing anything in a problem!
I was absent when my math teacher taught this so I’m here watching this. And yes, we have a test for math tomorrow. wowie
the x was easier to find, just think:
IF NADIA BOUGHT 3 CANDY BARS AND "4" FRUIT ROLLS FOR 2.84
AND PETER ALSO BOUGHT 3 CANDY BARS BUT "1" FRUIT ROLL FOR 1.79 we can assume that (2.84 - 1.79) is equal to 3 fruit rolls.
eventhough finding the x was my main problem...
@@user-le7lx4jz1u nice name lol
Why do I always feel sleepy when I do my homework?!
samee
what make me cry is when i do perfectly fine on the homework, but my mind goes blank whenever the test is placed in front of me. smh
Wow made it so much easier to understand
thank you so much. i was gone when we learned this in school and the teacher never got around to expalin this to me. this makes so much sense
This is better than listening to your teacher speaking something foreign for an hour
👍👍
What if they arent able to cancel each other out
I think the answer is No Solution. If both the equations cancel each other out, then the solution is 0.
One example of an impossible system of equations is this one:
x + y = 2
x + y = 0
If you solve these equations then you will get the nonsensical answer 0 = -2, which is clearly not right. =P
Then you make them cancel each other out
Laurelindo you know that their has to be a another equation and variables could mean one sooooo.....
rylan if they don't then u multiply or divide them until they do
Sal is a genius, in explaining these things.
How do we know whether to add or subtract the equations?
i just wanted a twinkie god damnit
Kantmiss Evergreen -add on- ELIZABETH
Thank you sir you did a great job
I hate math.... :(
Yeah. I love English... Math is ultimately pretty pointless.
I love English also!
+AtomizerVersion1 all shit we learn in school is pointless
Same English is my whole heart. I wanna write a book one day
HogwartsGleek every one hate math 😂😢😭
This dudes videos are better than anything any teacher does
Thanks man, you made this a lot easier to understand! Got my exam tomorrow!!!!
Phil Smith how did you do?
@Noah Sutherland 😂😂
@noahwifi fax 😂
Thank you!!! First three minutes were invaluable to me in understanding the fundamental concepts that make this method of solving linear equations "legal". I've understood how to do it for many years, now I know why it works. Thanks again!
ok Sal, how about you come take my test for me? :) you're a genius!!!
This is the second video I have watched and both have thought me more then my teacher in about less then half a class time
My class is the "flipped classroom" bs where my teacher makes us watch vague videos at home, and then doesn't explain in class. I usually end up here to help me with my math. Thank you Khan Academy!
If i only had this guy in my class.
10 years later and still helpin me on my algebra test
i love it now I can finally do my math right 😂😂😍
thank god i found this
My teacher has been trying to teach me this for 2 weeks and I watch a video a little over 10 mins and suddenly I understand
Learn more from this than my own teacher
before i watched this , i felt i was going to get a bad grade. now i feel cobnfident for the test tomorrow
Good explanation. Keep it up.
I'm glad we are learning this but when are we going to learn this in everyday life?
How linear systems are ever going to help you in the real world is a mystery to me
RIGHT
i love you, you are the best. Thank you for being born.
Thank his mom for being born
@@flashlightpaul1432 and dad...
THANK YOU THIS IS SO HELPFUL
YOU ARE SO HELPFUL!
Thank you so much. This video helped me so much.
how do we know when to add both equations or subtract them
Thank you so much, needed this.
My math teacher is bad at teaching and gets mad at the class when the whole class doesn't understand it. This guy makes it so easy and proves the point that my teacher is bad at teaching
Thanks
Thanks so much you helped me a lot man, thanks
I have a test tomorrow and after watching this I am only more confused than before
This is simply amazing
that happens to me all the time. multiply whichever one by the other kind of number (negative times whatever makes it the positive of the other number, Vice versa, and if there's something left over, you might have done something wrong so check your equation, it could be you forgot a negative sign
Sal teaches me more than my teacher 😂
Same 😂
Always so helpful wish my teacher could explain thing half this simple.
Where are you at now in life?
Why r online teachers much better than school ones
Love the graphics, great job explaining everything, thank you!
Soo much easier to understand, like finally after 3 years of not understanding elimination method..
Very helpful
Thankyou! These videos work like magic!^-^
Thank u so much, i understand alot from this thank u.
I love this guy. Whenever I don't get something I just come to him
ha same
You have saved my math grade🙏 thank you good sir
this helps a lot thanks
i literally have a math test on this in 25 minutes, skskkssk this helped, ty
update: my teacher wasnt here today, had a family emergency. supply didnt give us a test. good, i guess. i did not study more even though i had extra time to, lol
update to my update: my teacher came back the next day and made the test on the following monday. we did the test already, I live in Canada so the marks might be weird and not so good to any people out of Canada but I got an 85%, bless this channel :)
@@mylo1887 yessir
Prices from the 80s....
get FYI by CT byn
Vanilla Dazzle Dude really went from a normal kid to a wignat...
Yo how do you determine whether to add or sub?
he explained it in the video
towards the end
9:06
Monkey D. Luffy if it is a negative add if positive subtract
Eski toi to natsu d luffy sur fb? Mo kam ar toi sur fb
One video and I got the concept down already! Thanks!
Thank you so much I passed my exam because of you 😁
Khan academy is good
Its helped me get a c even though my target grade.was low
Helped a lot thanks
Great example thanks, I personally appreciate the fact that you do the examples "live" they are straight out of you head onto the page, not rehearsed. Thanks again
Someone give the guy a Nobel Prize!
I litterly has a test next period I’m scared
Perfect explanation👍👍
My only question is when do you subtract or add? Ugh im so frustratedddddd! I have a test next week and this is the only lesson i dont get!!
(11 months latee)Did you pass?
In 17 years, I have never thought math is this fun to learn!
Thank u so much, i couldnt find anythin good then i dound this
I swear ive been doing this in math for the past month and the way they did and explained it confused me bad but after this video i think i get it and its a much simpler way too
Really helped bro ty
Dude, I have an exam tomorrow and this literally changed the course of my exam. Thanks! You are really good at this stuff and I thank you for helping me understand this.
THANK YOU!!! I was gonna fail my test tomorrow
i looked all over youtube for this thanks
this was in the top..
These videos are so helpful, thank you very much.
have an exam in two days helped me alot
I have an exam tomorrow and this video is really helping me understand simultaneous equations
thank you. struggling with college level econ equations after being out of school for so long and this is saving my life right now! I was getting so frustrated
Whats that software you drew everything on? I need it for notes
I love this guy
how about if neither the x nor y disseapear in the elimination process
can you apply this rule even when the equations y or x's are different?
This helped A LOT! Thank you khan academy!
thanks teacher u are the best
I got the first part, but the second part confused me a bit.. can someone explain it?