Absolute value inequalities | Linear equations | Algebra I | Khan Academy

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  • Опубліковано 4 лют 2025

КОМЕНТАРІ • 642

  • @Peter_1986
    @Peter_1986 8 років тому +285

    2:59
    "You shouldn't be memorising any rules."
    That's a very good point - it is almost always better to develop a real intuition for things.

  • @SMTaha-en9ov
    @SMTaha-en9ov 9 років тому +324

    I studied my entire HIGH SCHOOL mathematics from Khan Academy.
    Khan Academy you are like an Angel in the Storm.
    :) :)
    :) :)
    :) :)

  • @jugglingisgreat
    @jugglingisgreat 9 років тому +437

    Thanks to you, I don't need to memorize the formula, because I actually UNDERSTAND what it means. Sal, thanks for all you do. We really appreciate it.

    • @wolfpig8719
      @wolfpig8719 7 років тому +3

      Ryan Smith I

    • @RichMiniön-r2m
      @RichMiniön-r2m 3 роки тому +1

      what formula.

    • @jprevard
      @jprevard 3 роки тому +1

      @@RichMiniön-r2m He means memorize rules for inequalities. It's easier to imagine (or draw) a number line representing an equation than it is to memorize rules. If you can imagine the number line, the solutions are intuitive.

    • @RichMiniön-r2m
      @RichMiniön-r2m 3 роки тому

      @@jprevard cap, num lines take too long

    • @Khalid.115
      @Khalid.115 3 роки тому

      @@RichMiniön-r2m You don't have to write all the numbers, just do it exactly like in the video.

  • @benfernandez-sheinbaum3558
    @benfernandez-sheinbaum3558 3 роки тому +231

    Here’s an inequality:
    1 Khan Academy video > 1 week of Algebra

    • @eswh8383
      @eswh8383 2 роки тому +5

      Fr

    • @gonzalo4658
      @gonzalo4658 2 роки тому

      Brian mclogan and organic chemistry teacher are better. Sal khan is a cringey harvard fetishist. Harvard people are never helpful at anything, and not because of esoteric scholarship but from actually being porous at explaining things. Khan-man’s an idiot

  • @laughinglauren8
    @laughinglauren8 14 років тому +46

    Mr. Khan, it's selfless and compassionate people like you who should run the world. Thank you for all that you do!

    • @die.87
      @die.87 Рік тому +2

      How are you doing now?

    • @die.87
      @die.87 Рік тому

      @user-eu3xh3zg2k Bruh

    • @beaniies
      @beaniies Рік тому

      ⁠@user-eu3xh3zg2kyou kids act like 12 years ago was a very long time ago

  • @mkyadav1334
    @mkyadav1334 9 років тому +831

    Forget textbooks, carry khan academy

  • @paisleyharris2007
    @paisleyharris2007 2 роки тому +41

    12 years later and this is still the best math course out there-

  • @seankandie3335
    @seankandie3335 3 роки тому +26

    I love how you explain things. You've helped me so much, I can only imagine the massive impact you've had in educating the world. Thank you Sal!

  • @SkillUpMobileGaming
    @SkillUpMobileGaming 8 років тому +14

    No textbook or video explains this better than you do, Khan!
    We all appreciate the hard work that you put into your videos because without you some of us would be lost.
    Khan, you are such a wonderful person!

  • @nancygatesmustdie
    @nancygatesmustdie 9 років тому +652

    im literally so lost right now im gonna fail my test tomorrow R.I.P.

  • @darkrebel123
    @darkrebel123 6 років тому +26

    Omg I've gone my whole life without understanding absolute value correctly. I'm studying for the GRE and was really struggling with these problems. Great video!

    • @ericb8217
      @ericb8217 5 років тому

      I'm studying for the GMAT. Did Khan academy help?

    • @iliketurtles5180
      @iliketurtles5180 Рік тому

      ​@@ericb8217Did Khan Academy help?

  • @anthonybassey8868
    @anthonybassey8868 10 років тому +195

    greatOR-----less thAND.......this helps.

    • @youremylovernow
      @youremylovernow 10 років тому +1

      do you by any chance go to kraemer and have ms. erskine...

    • @tycoon1661
      @tycoon1661 10 років тому +2

      Ashley Hong yes

    • @youremylovernow
      @youremylovernow 10 років тому +1

      Tycoon Bachra same...

    • @tycoon1661
      @tycoon1661 10 років тому +18

      hahaha i was just kidding i thought your comment was funny…you know asking someone on the internet if they are in your class...
      i actually don't have any clue on who mrs.erskine is...

    • @youremylovernow
      @youremylovernow 10 років тому +3

      Oh okay lol well idk she uses tht method wait youre not even the one who made this comment...

  • @ismellsomething1
    @ismellsomething1 12 років тому +1

    The best part of khans video is that he doesn't just want you to memorize it he actually wants you to understand what he's talkin about. My teachers should learn from you.Keep Up the great work khan!!!!!!

  • @Ben-qj6bg
    @Ben-qj6bg 8 років тому +658

    Upvote if you're studying for finals

    • @dulcevallejo3284
      @dulcevallejo3284 7 років тому +32

      Ben Wiley when the Reddit makes you forget how other apps work 🤣

    • @mya2317
      @mya2317 7 років тому +1

      Lol I cry

    • @h0rcrux774
      @h0rcrux774 7 років тому +1

      me too ;-;

    • @bobo5686
      @bobo5686 6 років тому +1

      ehh more to not to be kicked out of class this is hard.

    • @aliana8843
      @aliana8843 6 років тому

      nope a test

  • @rayray66
    @rayray66 2 роки тому +3

    Using intuition and thinking about the number line is great. I've been reviewing super old stuff but a textbook just had one memorize steps for each type of inequality without really explaining why you do things. With intuition I'll never forget how it works.

  • @Amarey269
    @Amarey269 14 років тому +6

    I always look for your tutorials first! you break it down into steps that are very simplistic. Thats how my mind needs to see it in order to do it on my own. I wanna know WHY we do something, and you tell that. Thanks so much!! Life saver for sure! ;-)

    • @justharsha2192
      @justharsha2192 3 роки тому +2

      11yr ago?!

    • @chrome1018
      @chrome1018 2 роки тому

      11 years huh, how are you doing now?

    • @nca4954
      @nca4954 2 роки тому

      .

    • @GrismarieGuzman
      @GrismarieGuzman Рік тому

      Genuinely curious where this person is and how they are doing 12 years later

  • @blessed275
    @blessed275 2 роки тому +3

    TYSM!!! My teacher is pregnant so she can't teach us fully, these videos really help me to study before and just get my clarification for her. You are a lifesaver :)

  • @isabellaxflynn
    @isabellaxflynn 7 років тому +2

    I have a massive algebra test tomorrow and I am rewatching these vids to help prepare. This really clarifies everything for me

  • @ComputareAccount
    @ComputareAccount Рік тому +2

    by 5 min of your video i understood more than my teacher's hour and half lecture

  • @YoYoYoYoYoYoPeace
    @YoYoYoYoYoYoPeace 7 років тому +5

    math exam tomorrow, and u taught this so well that after the first number line i could do the most complicated absolute values. Thanks man

  • @xeriana9052
    @xeriana9052 5 років тому +4

    bro I'm already a sophomore and I still didn't know how to solve absolute value inequalities. thank you so much this really helped a lot. I literally forgot everything I learned in middle school and my freshman year

  • @ramenx3034
    @ramenx3034 5 років тому +1

    Its ironic that if school teachers were good and explained the topic good this channel wouldn't be as popular or even exist.

  • @larrystylinson3309
    @larrystylinson3309 8 років тому +75

    Lol I have finals tomorrow and I completely forgot how to do this

    • @nooranameeri6746
      @nooranameeri6746 8 років тому +1

      Larry Stylinson oh lel me too

    • @MelodyLiuJade
      @MelodyLiuJade 8 років тому +3

      How were people having finals in December? I'm having my midterms now, and it's the middle of January.

    • @larrystylinson3309
      @larrystylinson3309 8 років тому +6

      Melody Liu I'm having midterms in two weeks as well, but I posted this comment on June 7th last year. At that time I was having finals. Btw that final was hard and none of this was even on it. I totally failed, but I think he curved it so I ended up getting a B :(.

    • @ritesha8050
      @ritesha8050 5 років тому

      lol

  • @jennamarcus4283
    @jennamarcus4283 10 років тому +8

    thank you so much, this video really cleared up my confusion. you explained things so clearly

  • @jackberning242
    @jackberning242 9 років тому

    There are like 3 people on youtube that teach me everything math. You are one of these people and I thank you.

  • @aarushiagarwal3210
    @aarushiagarwal3210 5 років тому +1

    Omg I wish all school teachers taught like this. Sal makes everything easier. I love him.

  • @hiitsmiya
    @hiitsmiya 8 років тому +68

    when u have finals tomorrow so u gotta remember everything u learned the entire semester

  • @CanadianDubstep
    @CanadianDubstep 11 років тому

    Understood more in 13 minutes than what my math teacher tried to explain in 2 hours. It's all about getting a different perspective on something people! That's how genius' think. If you don't understand something, look at it from a different perspective or find someone to explain it to you from a different perspective.

  • @Bigdredgen
    @Bigdredgen 3 роки тому +1

    I got a Math Mid-Term today so thanks.

  • @zuesr3277
    @zuesr3277 7 років тому +3

    I think this is the best video ever on ABSOLUTE INEQUALITIES.

  • @osun-ase
    @osun-ase 12 років тому +2

    Thanks for creating these! You make it easy to understand and you have a great speaking voice!

  • @abukicr7449
    @abukicr7449 Рік тому +1

    Its 2023 and still Thank you Khan

  • @minhdaman
    @minhdaman 2 роки тому +1

    Thanks! My son was failing his math, and now.. he ain’t a disappointment!

  • @GloriaStanley95
    @GloriaStanley95 14 років тому

    This is so awesome-thank you! this is a million times better than your own teacher because you can play this video over and over as many times as you need and you can pause the video, etc. - you can't pause a teacher

  • @mileycyrus20082010
    @mileycyrus20082010 8 років тому

    These videos help so much with sat questions! I prefer these videos over the sat specific ones! These help with content wholes in my prep work! Very helpful!!

    • @beri4138
      @beri4138 3 роки тому

      Why are you on every single math video

  • @t1msmurff990
    @t1msmurff990 Рік тому +1

    Thank you, man, you've taught me thing I had never could understand

  • @codemathlab
    @codemathlab 4 роки тому +1

    Khan academy always clears my doubt. It shows me reasons and how things are but my teacher just teaches the rules only.

  • @Ikhtesad
    @Ikhtesad 4 роки тому +1

    So eloquent and makes concepts so easy to understand. Thank you Mr Khan.

  • @Kar08Mie
    @Kar08Mie 11 років тому

    since you have to multiply both sides by 7, the 7 gets distributed to all terms. Terms are separated by a + or - sign.
    For example: if x + y = z, then you have to multiply all terms by a constant to keep the equation true: ax + ay = az. it is like saying a(x + y) = a(z), where the a has to be distributed.
    same is true with x-y=z --> ax-ay=az.
    same is also true with x+y>z (inequalities) if a is positive.
    in this case the constant, a, is 7 in the video.
    hope that makes sense!

  • @the_.undead14
    @the_.undead14 Рік тому

    Man tomorrow I have an exam and u helped me so much really thank you ur the best ❤❤❤

  • @discrete3511
    @discrete3511 2 роки тому +1

    At 8:55, it should have been and greater than not "or" greater than

  • @metallicwaffle
    @metallicwaffle 11 років тому +1

    Because of the definition of absolute value, the less sign means that a less absolute value set extends from 0 to a real number on one side of the number and from 0 to another real number on the other side, creating a spectrum of sorts. However, the plus sign signifies that the absolute value in question extends from a real number to positive infinity on one side of the line and from another real number to negative infinity on the other side, creating two separate spectrums. Make sense?

  • @nicolasvega1787
    @nicolasvega1787 Рік тому

    the way that you explained this made things so clear to me . drawing out the line to visualize was so helpful .thank you very much for taking the time to make this video!

  • @SalemAlhuwaiti
    @SalemAlhuwaiti 4 роки тому +1

    I have a midterm exam next week, and this video I want to thank you

  • @zarifshaukat9413
    @zarifshaukat9413 8 років тому +2

    Thank You So Much!!!!! I have a text on this on Monday and I finally understand this

  • @katynkitkat2
    @katynkitkat2 12 років тому

    thank you, thank you, thank you, thank you!!! i am taking an online summer math class and it never makes any sense till i watch and listen to you solve the problem!!! thank you!!! :D

  • @JohnDoe-iu5xi
    @JohnDoe-iu5xi 6 років тому +2

    wow. this is so easy after watching the first 1 minute. thanks!

  • @paulconsoli8168
    @paulconsoli8168 8 місяців тому

    didn't understand my class on this but didn't sweat it bc I knew I was gonna come here and boy did you deliver!

  • @diegotrujillo8001
    @diegotrujillo8001 9 років тому +4

    As always, amazing job. Really helps.
    Thank You

  • @canadanahuatl
    @canadanahuatl 6 років тому +3

    You're an awesome educator! thank you!!

  • @yasmiena3236
    @yasmiena3236 5 років тому

    this was super helpful im in algebra 2 and we are learning this and it made no sense with the teacher but now it makes so much more sense thank you

  • @Hunnymuffin321
    @Hunnymuffin321 11 років тому +1

    wow! i actually understand this, visualizing it with the number line really helped

  • @boushrahaider5176
    @boushrahaider5176 4 роки тому +1

    Shouldn't you swap the > or < when we have a negative number?

  • @CrazyPhilMachine
    @CrazyPhilMachine 10 років тому +4

    This has helped me so much THANK YOU

  • @AdmatHakodesh
    @AdmatHakodesh 12 років тому

    exponential functions with Absolute Value Inequalities are really tricky and deserve their own video.
    for example, try solving |x^2-9|>7
    not as easy as it seems, I guarentee...

  • @MoinuddinTarafdar
    @MoinuddinTarafdar 13 років тому

    @Jess07496 "and" is when the sign is "less than" "or" is used when the sign is "more than" - it is like this because when it is "less than" the line you make on the number line is connected because it includes solutions from the negetive side AND the positive side. But when it is "more than" the line is NOT continous and the solution is either from the negetive side OR the positive side. Sorry if it seems confusing...tried my best to explain.

  • @steelpanther88
    @steelpanther88 8 років тому +1

    thank you for explaining in effective reasoning the absolute value concept

  • @Attalla-t9b
    @Attalla-t9b Рік тому

    The way you explained it so clearly makes me wanna cry 😭😭

  • @ruffy7679
    @ruffy7679 6 років тому +1

    i can’t understand my teachers teaching but this video actually made me get the hang of it

  • @nickaguirre6317
    @nickaguirre6317 4 роки тому

    I was looking for a video with explanations and not memorizations. Thank you so much!

  • @calebjohnson692
    @calebjohnson692 7 років тому +1

    you saved me from my algebra class thankyou

  • @catherinesteigerwald1659
    @catherinesteigerwald1659 10 років тому +4

    hey if you could please, what are you using for the note writing??? it would help greatly with math

    • @spot5890
      @spot5890 9 років тому +1

      i'm almost sure he's using photoshop and just zooming in

    • @dhruvg550
      @dhruvg550 9 років тому

      Camtasia Recorder ($200) + SmoothDraw3(Free) + a Wacom Bamboo Tablet ($80) on a PC. He previously used ScreenVideoRecorder($20) and Microsoft Paint (Free).
      Source: qr.ae/RoQmZ5

  • @Avengeill
    @Avengeill 13 років тому +1

    @imwithdumbhead The sign changes only when you are multiplying or dividing with a negative number if I am correct

  • @nikollasnatsios
    @nikollasnatsios 9 років тому +5

    Thanks you helped me remember

  • @jeuzy
    @jeuzy 12 років тому

    You saved my butt sir, I didn't have a clear grasp on absolute value and inequalities and absolute value earlier in class today, but now it is crystal clear (well, almost)!

  • @mritunjay2624
    @mritunjay2624 6 років тому

    First 9th grade then 10th and now current 11th.. text books changed ..teachers changed..school changed ..but sal is still there ..thanks a lot..

  • @shahadar4555
    @shahadar4555 3 роки тому

    الفيديو درته قبل 11سنه وفي ناس الي2021تشاهد فيه ❤️❤️❤️شكرا علي مجهوداتك الرائعه

  • @babycarrotz32
    @babycarrotz32 Рік тому

    Studying three hours before my Algebra two test. This guy is a godsend.

  • @xheatx9610
    @xheatx9610 2 роки тому

    thank u ive been struggling and you have helped me alot

  • @m7zu323
    @m7zu323 2 роки тому

    man i love khan academy saved me 3 times from finals in math

  • @SilverFilmsStudio
    @SilverFilmsStudio 12 років тому +1

    Thank you so much!!!! I have an exam tomorrow with this on it!

  • @alejandrakarinabarrientosl1740
    @alejandrakarinabarrientosl1740 9 років тому +19

    look guys:
    absolute < # } and
    value
    absolute > # } or
    value
    hope you all understand!! love ya

  • @ismael0479
    @ismael0479 6 років тому

    In class we went over this for two weeks and never understood it until I watched this video and finally got the hang of it

  • @tocommentonvids
    @tocommentonvids 11 років тому

    brilliant explanation. yet another video that proves why khan academy is so effective.

  • @WalkableWe
    @WalkableWe 10 років тому +8

    Greater Or = GO
    Less than And = LA
    GO LA!

  • @Ayybob
    @Ayybob 5 років тому

    Wow. All through high school and now in university. I finally understand what absolute value means.

  • @curiouslearner1020
    @curiouslearner1020 6 років тому

    Very well explained, guys if you don't get this first study the concept of graphical solutions of inequality and intervals then u will surely understand this

  • @cdaniellemalimban
    @cdaniellemalimban 9 років тому +2

    030916
    Final exams tomorrow. Hope this'll help me.
    Thank you Khan Academy :D

  • @ana_cjb5483
    @ana_cjb5483 8 років тому

    At 4:18 ur supposed to set |7x|= to -21 and 21 and divide seven and then u get ur two points.

  • @arsonhycan
    @arsonhycan 4 роки тому +1

    10 years ago and it's still relevant

    • @beri4138
      @beri4138 3 роки тому +2

      It's math why would it not be relevant lmao

  • @AverageYoutuber6615
    @AverageYoutuber6615 2 роки тому

    THANK YOU Sal !!! even after years of you're videos being on here its Helped me understand Absolute value inequalities !!! thank you SO Much 😁😃

  • @saaqibmahmood5495
    @saaqibmahmood5495 4 місяці тому

    I think a better way of doing |5x+3| < 7 would be to write it in the equivalent form -7 < 5x+3 < 7, and then proceed from that.

  • @MDUBB94
    @MDUBB94 12 років тому +3

    If you are drawing with a mouse, I am amazed at the neatness!

  • @ky-ik3cz
    @ky-ik3cz 2 роки тому

    Ive always just memorised formulas. Understanding whats happening here has made it easier for me to solve them by just looking at the equation, because I understand what is happening

  • @oghenekomeegbevurie9205
    @oghenekomeegbevurie9205 4 роки тому +10

    I can't believe this was 10 yrs ago

  • @kendrickjudemausisa6069
    @kendrickjudemausisa6069 6 років тому

    Thanks for the clarification Sal! Now I understand why the intervals point where!

  • @strawberry0898
    @strawberry0898 6 років тому +1

    Thank you so much, your explanation was easy to understand. Thxxxx!

  • @fundamentalsofphysicsnmath4306
    @fundamentalsofphysicsnmath4306 2 роки тому

    Thanks for such a nice explanation. Love you from India...........

  • @ashishchongtham5315
    @ashishchongtham5315 4 роки тому

    Thank You for clearing out doubts all the time

  • @ghostyvids9825
    @ghostyvids9825 3 роки тому

    Thank you sal you are the best you just showed me a 13 minute video and thats one month of math

  • @leulwosen4436
    @leulwosen4436 4 роки тому +1

    Thank you was having a little trouble with this.

  • @johnwobube1679
    @johnwobube1679 2 роки тому +1

    Wow! Amazing tutorials

  • @mehejabinniti9726
    @mehejabinniti9726 4 роки тому

    thanks. I am a new viewer of your chanel, this helped me

  • @elellta
    @elellta 4 роки тому

    I need a better algebra 2 teacher. thank you Kahn academy

  • @Kar08Mie
    @Kar08Mie 11 років тому

    What is the mathematical rationale for why > results in "or" and < results in "and". It makes sense, but just trying to understand it from a mathematical perspective.

  • @ultimatepirate9589
    @ultimatepirate9589 8 років тому +5

    homestudying a levels and khan became my math bff XD

  • @karalipbalm22
    @karalipbalm22 10 років тому +7

    This is amazing, this just saved my grade for this unit!!!

  • @shahadar4555
    @shahadar4555 3 роки тому

    اشكرك كثيرا ❤️❤️

  • @bigdaddydominator5446
    @bigdaddydominator5446 5 років тому +2

    I'm ready for my test now

  • @zultra6114
    @zultra6114 9 років тому +1

    Thanks a lot , it really helped. 😊