Algebra: Linear Equations 2

[iamtheboss19]

i wish you were my teacher!

[ambarigreyson3000]

lol i shouldve been practicing during the break not last minute lol

[zombieslayer799]

@ambarigreyson3000 bro me too.!it sucks -.- lol xD

[Kevinpitviperorton]

WHO GOES TO MEIGS MAGNET MIDDLE SCHOOL SEND LETTER IF U DO

[Ingi0m4r]

i hate fractions,

[weekendswithme]

thumbs up if you have a maths test tomorow

[sindhi03337959007]

Urdu Main Hota Tu Acha Hota

[skc12731]

kwl vid really helped

[sdurgefafd]

damn, he explains much better than my maths teacher..

[jesontheG6]

i like the way you say let's do another problem

[ridoymonie]

lol i play too

server ip: 207.210.254.133:255625

[ridoymonie]

hmm Minecraftsp

[ridoymonie]

wat

[ridoymonie]

yeh i do

[ridoymonie]

dos any1 play a game NOT maths

[ridoymonie]

i lernt 1 ting witch is .......

the whole of algebra

i lik maths in all education cause of this khan guy he ROCKS!

[123ilovevolleyball7]

im trying to go to pre algerba at my school and were doing these but no fractions...do you have a video on that??

[pigfacescool]

omg it is before the test

[macdonaldlak1]

OMG this guy makes math fun, and normally I wouldn't say that! He makes life bearable. I love you :) (jk).

[FacultyBob]

still dont get it

[MrSunjester]

@FacultyBob then you need to go back to more basic stuff, I constantly have to keep backtracking to figure this shit out

[XuXKrissyXuX]

@Blackreaper95 12 is the least common multiple of 6 and 4. (6) ,6,12 - (4) ,4,8,12

[Blackreaper95]

How did he get 12

[Tinaf36]

Ummm... I totally didn't get that one?!

[TheHabbo210]

trigonometery is easy. You should get what you want. Good Luck

[djemmet1]

its just i have a algebra and triganomictry test tomorrow and wanted to refresh my mind and its done just that thanks. i will hope to get a A* tomorrow.:)

[djemmet1]

oh yes thanks for this information. there are many more steps that are faster than the actual means of your answer but i do understand you. :) thanks

[99airsoftboy]

I think that we should all say thank you to sal khan for his dedicaton and willingness to help others. Keep up the great work!!

[SaberZoro]

Thankyou so much this really helped me under stand it better especially the fractions.

[honduras4lifeputo]

i hate math i got bored at 1 minute in the video shit

[chrisgabenathanfrank]

Never mind I understand now

[chrisgabenathanfrank]

i just don't understand where you got the nine and ten.

[2010stupidass]

Holy shit I can't understand math theres to much steps and so many other problems don't get confused of my username I came up with it when I was 9 okay and yes I'm not happy with it I'm smart I'm not going to lie but math is something I can't fit In my head there to much of it I have state testing TODAY and I'm going to fail in math :,( oh god (sigh)

[monicashver]

This is helpful! Thanks, im hoping for a good mark on my math test!

[SwirlingChords]

This is easier than Linear Equations 1.

[TwistedPencils]

@SwirlingChords cause this is pretty much the basics.

[sergemankool]

This video has better explanation the my teachers explanation! Thank you! I am now ready for the test tommorow!

[mars8254]

@sergemankool LOL AT PEOPLE LIKE US LOOKIN AT THIS A DAY BEFORE THE TEST..

[patkaybites]

@mars8254 Exactly xD Just before the test. HAHA.

[spencervirtuecycling]

@mars8254  day of the test**

[sergemankool]

This video has better explanation the my teachers explanation! Thank you!

[aida1887]

Thanks sooo much you explain things just the way I need it lol!!! =)

[BombDaBase1]

2:07 its funny how how i just divided by 2 but you went all out on that problem.

[knightsintodreams]

i'm about to take the SAT's after not doing algebra for 6 years, and so far i've gotten EVERY problem wrong at some point lol. i keep going, "oh right, you ADD both sides of the equal sign" or whatever.

thank god for khan!!! you're saving my life!!

[iDanielVideo]

haha he drew a dick

[ihatesasquatch]

@iDanielVideo Timetag or it didn't happen.

[iDanielVideo]

@ihatesasquatch 4:13 to the right of the fraction (balls not included :)

[ihatesasquatch]

@iDanielVideo Ah yes, I see. Needs balls.

[2468ronald]

sry man i was making fun of u when u was teachin addition level 1 but i didnt realize u had more advanced stuff now u r actually helping me lol sorry

[xshadw]

@2468ronald noob

[lennon205]

excellent teacher and I can't beleive he does this for no profit !

[ecua407s]

i wish i had your brains

[Osmalls13]

can u plz help me on this linear equation.... x = 2/3x - 1

i can't figured out : (

[chantalitaspic]

P.s for those that dont understand him i think it's time for you to get a home tutor because if you cant understand thing guy then your really dumb because he gives you very basic steps and shows every bet of work !!!!! so stop dissen him

[SuperFeimer]

@chantalitaspic Sorry your highness, we are not all blessed with your huge intelect and amazing insight into Linear Algebra.

[chantalitaspic]

this is the best video for help with math he's very easy to understand and put things in term someone can actually  understand. compared to all thesee other waste of time videos that get posted on youtube. hahahaha Thank you :)

[Appleboy05]

man u r so confusingg...u don explain why you are doing things and everything on the board gets all over the place and confusing ..plz man do something else so that dumb ppl like me could understand it

[harrygutterballs]

@Appleboy05 stop over thinking the problem, just follow the steps and do them over and over again until it's clear, you need to know the basics before taking on a algebra question.....

[bboyloco3]

i love you because of you i'm a genius at every single math stage except calculus.

[hoodsteezz1595]

i dont get it y u moved your 3 on da other side and how is dat 3 negative



[hoodsteezz1595]

i dont get it y u moved your 3 on da other side and how is dat 3 negetive

[Time4Me2GoHARD]

PENIS AT 4:03

[varshikajesus]

THE WAY U TEACH IS AWESOME!!! THANKYOU!~!

[vaironxxrd]

i still dont understand how do you do the 10-9 Thing

Can someone explain

[jam94banjo]

@vaironxxrd When you subtract fractions they need to have the same denominator (the number below the solidus)(solidus = the line). To get the same denominator you need to find the LCM (lowest common multiple) of 6 and 4. The LCM is 12. For the denominator of 5/6 to become 12 you must multiply by 2 so it becomes 10/12. For the denominator of 3/4 to become 12 you must multiply by 3 so it becomes 9/12. Now you have the same denominator you can subtract the fractions which is why he put 10-9/12.

[aqwrule]

THIS GUY IS AWESOME

THUNMBS UP IF U AGREE

[richard1237123]

what if..

the problem is..

2x+2=-15 ?

how to solve it?

please reply.

thank you!! ^_^

[0bsolete]

@richard1237123

Wouldn't it be x= 13/2?

[cajun41795]

well how did u get 10?

[nickxo419]

ya'll are some pussy fucks that dont understand anything

now shut up and learn

godamit

;)

[herreramarlen1129]

No se como explicarlo en ingles! pero en donde la mayoria de todos nos confundimos fue en 4:01 donde saca 10-9/12! lo q paso fue q busco un comun denominador y en este caso fue el 12!!! entonces deigamos q para q 4 multiplicado por un numero t da doce entonces 4x3=12 y eso tambien lo iso en la parte de arriba multiplico 3x3=9 Y lo mimo lo iso del otro lado multiplico 6x2=12 y 5x2=10! Y de ai fue de donde saco 10-9/12! espero y esto aiga ayudado!

[Djcrazykidd]

I fucking hae when he doesn't go step by step 5:26, I'm not too bad at this ,but to some one really learning this for the first time ,that could really fuck their shit up.

[kratos223]

@Djcrazykidd No man, anyone with a head can figure that much out.

[brucybabe212]

on the frist problem 1half times 2 = 1x ,but you did not add the 1 how come??

[Djcrazykidd]

you cross multiply5-4,and 6-3.

[Djcrazykidd]

You lost me at 4:02 how did you get 10 minus 9 over 12?

[rasas1235]

Over 12, to make its denometer are same. 5/6 times 2 = 10/12 and -3/4 times 3 = -9/12.

So 10/6 - 9/12 can write as (10-9)/12. Hope this can make you understand. Before can make fraction minus fraction, make sure its denometer are same. Thanks.

[rasas1235]

This is to answer Djcrazykidd question

[Djcrazykidd]

@rasas1235 THANKYOU....MY GOD YOU DID A BETTER JOB EXPLAINING IT THEN THIS GUY!! THANKS BRO.

[farshadguitar]

thumbs up if you believe this guy deserves the nobel prize !

[hatrancl]

where did you get the 10 - 9? and the 1/6 at the end?

[TheMikeymouse1234]

yes thanks

[kikinchacha]

TY I am back in algebra after 20 years! This totally helps!!

[jhnggg]

must be asian

[blazemaster5506]

@jhnggg lol he is

[skinnytwintights]

i. love. you

[pgochnour]

I haven't had algebra in 20 years. Taking exam for nursing school. You are my hero too! Great teaching skills!!!!!

[taylorsks101]

i multiplied the 5/6 and -3/4 and simplifyed and still got 1/12?!?!?!?! i paused to work it out, then i saw u added and im like aww i got it wrong but i was like OMG btw ty for the help, my teachers never really taught me this stuff well, and well you a hero!!!!

[elmono10465]

shut the fuck up

[sil3ntmode]

I just wish I was educated in US yo, I would lo ve math. I mean I still am only not that so much intersted in it.

[FBICIA911]

very simple !

[TheMujee]

khanacademy thanks a lot

[kingpalash]

i did nt understnd hw u got 10-9/12 from the above??

[TheMujee]

@kingpalash

12/6=2*5=10

12/4=3*3=9

i hope u got it

[eternallight351]

@TheMujee thanks i was just thinking about this...

[skinnytwintights]

@kingpalash i know right. im confused.

[chrispuremexican]

im at the store

[TwoAndHalfMidgets]

buddy, you're my damn hero. you just saved my 6 weeks of summer school

[beaner7468]

confused me at first saying minus when it's negative am I right ?

[MrPASHproductions]

yeah it can bre said minus or negative just depends on where uu r from i guess

[wildgirl13100]

I noticed that when you had to do 5/6 - 3/4 you went a really difficult, confusing and roundabout way. I did the same problem on my own, and got the same answer. Try to make things simpler. I like this video, but that thing really confused me.

[wildgirl13100]

Thank you so much! So far I have been getting a C in math, but now I think I can get an A! You rock!

[MegaEyasu]

I like the way you teach, thank you. I am getting it.

[keithgarry]

Why does the order of operation start with addition/subtraction?

[koriko88]

Because the South Asians invented algebra and they wanted it that way. When you invent something, you get to set all the rules. :-)

[Spike116s]

It ENDS w/ addition/subtraction. PEMDAS

[keithgarry]

how so? did you watch the video the first thing he does is subtract.

[Koseiku]

Good.

[HowAboutSomeTruth1]

Damn I kept multiplying 3/4 by 4/3 to cancel it out instead of subtracting it.

How do I know when to divided, multiply or subtract to cancel the number out?

[lotteryinbabylon]

If the coefficient (the number in front of the x) is a whole number, you divide. If the coefficient is dividing the x (i.e. x/3) you multiply.

When you want to add like terms on either side of an equation (x-3=5), you do the opposite operation of the sign in front of a term. So in that example, you would add the 3 (minus sign in front of the 3) to the 5 to get 8.

Hope that helped!

[Seattle206723]

What he did on the left side was add+ -3/4  to cancel out the positive 3/4.

Then what he did on the right is a bit confusing for me. He spoke 3:39 we have to do this addition fraction or subtraction fraction.

My question is could you do addition instead of the subtraction he did?

[lotteryinbabylon]

Adding a negative 3/4 is the same as subtracting a positive 3/4. Adding any negative value is the same as subtracting a positive value. You are doing the same operation.

He does this to isolate the variable x (you want your x's on one side, and your non-x's on another.)

Hopefully that helps, if not, let me know and I'll try to provide some more insight.

[alcolo176]

thanks a lot for the vid.

[carolfranklin7072007]

Thank you

I am getting ready for college algebra and i need you

again thank you

[sharpsh00ter123]

thanks its awesome how someone can be bothered to help someone

[kevinmarmet]

@sharpsh00ter123

Agreed. Most people dont even care

[airtwaine]

@sharpsh00ter123 he gets paid for it



[loveistheway777]

good!

[Neptune4000]

I'm confused about how you got 10-9 over 12 can someone help me? thanks

[digforbear]

(5/6)-(3/4)

->(5/6)*(2/2) - (3/4)*(3/3) = (10-9)/12

He multiplied the each fraction so that the denominator would equal 12, so he mulitplied 5/6 by 2/2 which comes out to 10/12 then he multiplied 3/4 by 3/3 which equals 9/12

10/12 - 9/12 = (10-9)/12

he can multiply by 2/2 and 3/3 because they both equal 1, and you don't change a number when you multiply it by 1

[icedece82]

In order to subtract the 3/4 from 5/6, you have to make sure that the denominator of each fraction is the same. In this case he uses 12 as both 6(x2) and 4(x3) go into 12. But because this has changed, the numerator also has to change by multiplying the top number by whatever number the denominator was multiplied by to get 12. Here it is 5x2 as 6x2=12 and 3x3 as 4x3=12. This makes 10 and 9 which are then placed over the 12 in order to tidy it up as (10-9)/12 is the same as 10/12 - 9/12.

[TurismoHD]

He canceled out 3/4 on both sides, which left him with 5/6 - 3/4. What he did then is find the Lowest Common Denominator, which is 12, so he needed to multiply the numerators of the fractions by whatever multiple the denominator need in order to reach 12. So for 6, that would be 2, so 2 times the numerator (5), and for 3/4, multiply both by 3. Therefore he's left with 10-9/12.

[ilovemybod1]

i wish u would explain a little more about why u do things..

[rosariosamuelD]

ok well ive seen some of the videos and they're awesome but not what i need so far. im trying to figure out equasions like.

4(z-1)+1=21 and i think that i may know how to do it but i cant be possative. so i know you distribute 4z and make it 4z-4 i think and then take 4 and subtract it by 1 and get whatever and i dont know what to do from there. any suggestions?

[Zeinkaps]

everything u said is right and after u get 4z-3=21

u add 3 to both sides, that way 4z is by itself. so its 4z=24 divide 4 to both sides, z= 6

u can check it, by replacing z with 6.

[rosariosamuelD]

thanks. my math teacher told me how to do it today. but thanks for the help anyway

[Wafflesmart]

One way to do it is this.

First do z-1, z-1=x

so 4(x)+1=21

this means that 4(x)=20

20 divided by 4 equals 5

so x must equal five

This means that z equals 6

so 4(6-1)+1=21

That way might be kind of complicated for some people, but I think that it is the easiest way to do it.

[malubayraymond]

this really helped me, thanks sir

[DivineWisdom777]

tpriceballa he didnt get it wrong because he checked it out and it cleared but i wonder what step he used to get 10-9 ....

[DivineWisdom777]

sam how did you get 10-9 over 12 what did you use to get that add/sub/divide/? i know 12 is common factor but 10-9 ?

3:40 is the time where you solve it

[pstcontrl]

DivineWisdom777, to subtract two fractions you have to find the common denominator. The smallest common denominator of 6 and 4 is 12. You get 12 by multiplying 6 by 2 (6x2=12), and 4 by 3 (4x3=12). If you change the denominator, you must change the numerator too of course. You have then to multiply each numerator by the same number you did the denominator. So you have to multiply 5 by 2 (5x2=10), and 3 by 3 (3x3=9). That is where 10 and 9 came from. I hope that helps.

[Yieiuu]

You cared enough to click.

[tapplesauce]

about math?

Lots of people care because they want to start their careers.

[tjfromga]

my head hurts lol!

[MightyMite76]

ok,,,

Problem: 4y - 4 + y + 24 = 6y + 20 = 4y

Solution: y=0

Problem: 5x + 3 = 2x + 15

Solution: x=4

My question is what route should I take to come up with each of those solutions? I need step by step, by step, by step instructions.

Please help. It's been a while.

[emotionalpunkboy]

WELL IT Makes a perfect sense but in my country we learn American 10th grade algebra in 7th grade so it is so hard for me

[SuperHeroMan411]

algebra is a load of bull shit we dont need to know

[tapplesauce]

Really?

You obviously don't know much about technology. And if you don't need to know about algebra, why did you come here? I'm just saying...

That's your opinion but why would you come here?

[aarron555]

Kinda got stumped on the 10-9 / 12 part. Worked it out though. Thanks for the videos. :)

[jennifersometimes]

I'm confused. :[

[Readingiseasy]

I fell asleep a long time ago... 0__- z zZZz

[benjoandrichie]

then how did you write this comment

[Readingiseasy]

i wrote it with yo moma pussy how that?.

(benjoandrichie)

[benjoandrichie]

lolz dat r must haz taken a long time

[bassman1201]

This is a sort of low level way to do this problem. Here is my way:

-1/2 + 3/4 = 5/6 . Then I would multiply the entire problem by 12 = LCM

Then you have all whole numbers, like how that works?

You get: -6x +9 = 10

-6x = 1

x = -1/6

Much easier.

I am a Algebra one student. THat is my war.

[maryyanna1]

wat!!!!!!!!!!!!!!!!!!!!!!!!!!!­!!!!!

[Aphiticus]

On the equation -1/2x+3/4=5/6, i didnt understand how you went from -1/2x then did the reciprocol of -2/1? Isnt it suppose to be the opposite making it a positive 2/1? When i did the equation i got a positive X=1/6 and when i did the check, i still got the answer correct?

[raztuss]

You should explain how you came up with the 1/12 plus 9/12 as a refresher or reminder.

Show the step, but it was still helpful.

Some might not know how you got there.

Thanks

Awesome help.

[DefJay7]

1/12 + 3/4 = 1*4/12*4 + 3*12/4*12 = 4/48 + 36/48 = 40/48 the same thing as 10/12 which is the same thing as 5/6<--and there you have it.

Raztuss im sure u know this..i just wrote this for the people who dont:)

[cocoolio]

thank you u r very helpfull man!

[danhinsperger]

i like you

[mariojkid]

Algebra: Linear Equations 2 is easier then Algebra: Linear Equations 1

[ihachi474]

Thank Youuuuuuuuuu!

[luigiisawsome85]

awsome

[reason285]

review how to add and subtract fractions and you will understand

[ballocoke]

i dont understand thw 10-9 over 12.wouldnt the step be 5-3 is 2 and 6-4 is 2? im confused at that step.

[jonray107]

for subtraction u still use the lcm and do it like that, but for multplication and division u can do it like u described.

[gokumadara]

im also confused with that part 5 over 6 is 12 i mean logically that makes no sense

[arkdude211]

to add and subtract fractions, you need to find the lowest common denominator. because the lowest common denominator of 6 and 4 is 12, you must multiply the numerator by the same number that you multiplied the denominator by to get 12: Numerator: 5*2=10

denominator: 6*2=12

get it? if not have mom or dad explain

[robfletcher2]

I want your babies.

Love

Bob

[watergirl666]

at 3:45 i am not sure how he got the 10-9 over 12. i always thought i was supposed to multiply the numbers across once i got the LCM. but i dont get the same answer by mutiplying 5x3. so someone explain how he got that answer?

[majorkeybaree]

yes you khan

[7Claudio10]

Ma In Italiano Non C'è?

[LzI]

I had the worst math teacher ever, and now i quit my math and im taking it this way instead. I love the way Khan explains things. This is great! :)

(and i dont have to pay $1000 for the course)

[wertnoel]

why did 3 become 0????

[vickiormindyb]

If he had placed the -3 beside the 3 on the left hand side of the equation it would look like this: 2x + 3 - 3= -15-3.

+3-3 = 0.

I hope that helped. I'm not a teacher, but I took Algebra I before; I forgot it all after an accident. I'm learning it again, but some things are coming back through his explanations.

He's really wonderful, because he never doubted I could learn it again. The Math teacher I had before him told me I was wasting my time, that I'll never learn anything to do with Math.

[qjslamma]

i hate teachers like that, mine said that I was wasting my time trying to get anything higher than a C(but i ended up finishing the year with an A average, i guess i wasted my time that whole year then)

[amozoness6]

Good for you. (no sarcasm)

[turningheadfart]

-3 and +3 when COMBINED =0 thats what u wanna do cancel everything so u get the variable alone and what u do to one side do to other

[alexia942]

Because you are taking 3 from each side. Once you take 3 from the left side of the equation it no longer exists on that side.

[ro0665]

dude thanks this helped me a lot

[Boozjee]

I like the way you write out the equations more horizontally rather than the vertical way I was taught. It's a lot cleaner and easier to read.

Keep making these videos!

[Regplex]

i agree!.. my teacher uses a vertical style and seeing it horizontally does give a new perspective!