I showed this video in class and we found an error. The part when you divided the second equation by 4. You forgot to divide 6 by 4. I had to correct it in class and explain it to my students. On the brighter side of this experience, I realized that my students understand the lesson because they easily identified the error in the video, which means they dont just watch it but they are really paying attention to the process.
I was glad to see that others noticed the error in the y-intercept. I'm a teacher too and it is common to make errors while writing on the white board. I rely on my students to help me out and point out my mistakes.
@@matthewherzeca3251 i mean, you really shouldn't answer a question, you have no idea about. you're going all over the place, saying it can't be a fraction. Dude, take any graphing software, and plugin a y = mx + c, where c is a fraction, and no, your house doesn't blow up! It works!
When simplifying the second inequality, you accidentally lost the denominator in 6/4. It can't just disappear. What you wanted to do was to keep 6/4 and then simplify it to 3/2 (or 1½). Thus the reference line should have started with the y-intercept of 3/2 (1½) and then had a slope of -1/4 from there. And to Matthew Herzeca, you absolutely *can* have an intercept that is a fraction.
This was a huge help! Thank you! By the way, Sal Khan made a simple error and we all know what the real answer is and how to do it so stop complaining.
What if you have an equation that has the y intercept bigger than the graph. For example if I have x+y is less or equal to 200 and 5x+6y is greater or equal to 500. Even if I put the equation in y=mx+b form, the y intercept is still big so how do I graph that on a graph that just the y axis goes up til 10 and how do I graph the slope?
In the second example, why is the y intercept 6, instead of 6/4 or 3/2? Both sides had to be divided by four, so that should make 6 become 6 over 4, right?
He decided to make it happen. If he should have divided 6 by 4 the result would be 1.5 or round off 2. But maybe the y should have been between the 1 and 2. Then solve the slope.
Short Answer: You go up 4 and over (to the right) 1. (Explanation below) _________________________________________ Explanation: I personally prefer using rise over run, which is the same method he used, but he just flipped it (run over rise), which is more confusing to people who don’t know how to do it. So in your situation you can turn the slope (rate of change), which is 4, into 4/1, since 4/1 still = 4. So then when graphing you would start at -7 on the y-axis AKA (0,-7), and rise (go up) 4 and over (right) 1 and repeat. Once you run out of room on the graph, unless you want to just use a ruler to draw your line, which is less accurate, you go back to the starting point (0,-7), using the slope, and go in reverse. Since -4/-1 also = 4, then you can start at (0,-7) and go down 4 and over (to the left) 1 and repeat. Also, in the situation, when connecting the points, if your line is going downwards from the left to the right of the graph (negative/decreasing), then it’s wrong. Because 4 is a positive (increasing) number so your line should go up from the left to the right of the graph, because it’s increasing. However, you can’t use -4/1 or 4/-1 as they both = -4 instead of 4. So using -4 as the slope would make your line negative/decreasing and make your graph incorrect.
When you do the second equation you divide both sides by 4 and there is 6/4 and you say it is just 6 when you move on. Is this an error or is there a reason why you did this?
With systems of equations there is one set answer, but with inequalities there is not one set answer. From my knowledge the only way you can is from using sub. to plug in points for the x and y. Example y>1x+2; y1(3)+2 and the same for other inequalities. You check and see if it’s a true statement
This dude has taught me more stuff about math than my actual math teacher. Just because he made one little mistake -you know the thing that separates humans from machines- You start criticizing him. So sad. I bet you are watching this video to get help, aren't you?
I thought I was dumb, I’m glad others see the 6/4 error You would think a big company made to help teach kids would be better about checking their content
There is an error present in the video. When writing out the second inequality, the y-intercept is wrong and therefore, it should be 3/2.
checking the comments to make sure I wasn't crazy. Thanks!
I think i was wrong or i miss any steps! Thanks for checking
thank u
it’s funny how this video explains more than my algebra teacher
Ikr
fr
In less time too lol
Crazy how you are either a senior or done with high school now
@@Syydontmiss senior 😭😭😭
At 3:40 why does 6/4 = 6?
The y intercept can't be a fraction
***** or decimal. If have something that can't divide into a perfect number (like 3) than don't divide it.
+Clorox Bleach
that's not how it works
It's an error
The y-intercept can be a fraction.
I hate math
Math hates you
OOF.
i hate
math but its cool
Al527 Shut up
@@Al-xi8vu You are right. It's true because math ruins our life. So math is just evil to us.
I showed this video in class and we found an error. The part when you divided the second equation by 4. You forgot to divide 6 by 4. I had to correct it in class and explain it to my students. On the brighter side of this experience, I realized that my students understand the lesson because they easily identified the error in the video, which means they dont just watch it but they are really paying attention to the process.
In that case, he totally did it on purpose
@@masalagravy6061 LOL
Math makes me feel stupid 😂
It's normal for me to feel "stupid" when i watch maths everyday, just like how it feels when you adapt to something uncomfortable.
@@sukarnos3xy u had to ruin it didn't you?
@@wonderthegoat Sorry, no debates please.
@@sukarnos3xy ez win
I was glad to see that others noticed the error in the y-intercept. I'm a teacher too and it is common to make errors while writing on the white board. I rely on my students to help me out and point out my mistakes.
sorry if this sounds like a dumb question but how do you get 6/4 to equal 6? ahhh i see I' am not the only one asking this question
The y intercept can't be a fraction
he did a mistake
I was thinking the same thing, like what?
@@matthewherzeca3251 it can be fraction
@@matthewherzeca3251 i mean, you really shouldn't answer a question, you have no idea about. you're going all over the place, saying it can't be a fraction. Dude, take any graphing software, and plugin a y = mx + c, where c is a fraction, and no, your house doesn't blow up! It works!
When simplifying the second inequality, you accidentally lost the denominator in 6/4. It can't just disappear. What you wanted to do was to keep 6/4 and then simplify it to 3/2 (or 1½). Thus the reference line should have started with the y-intercept of 3/2 (1½) and then had a slope of -1/4 from there. And to Matthew Herzeca, you absolutely *can* have an intercept that is a fraction.
yeah, that guy's going around driving people bonkers!
im taking two highschool classes early while doing 8th grade at the same time and my math eoc is next week. this helped so much!
Thanks man you are better than any teacher I have ever had
watching this on sunday at 11pm because test is Monday morning at 7:30
Did you do well?
hell nah
Emily Walker Thursday 3am ; test is Thursday 7:45 😂
haha!
My teacher says it is rise over run
I understood this better than what my teacher was teaching for 2 weeks. Thank you
Thank you so much. Also I think you made a mistake solving the second inequality. The y- intercept is equal to 6/4.
I suggest using the rise over run term when graphing, it helps you remember
This was a huge help! Thank you! By the way, Sal Khan made a simple error and we all know what the real answer is and how to do it so stop complaining.
hey guys on who are watching this on sunday
i have finals tomorrow
Hah me
i’m watching this on saturday
oh hey wassup
@@era2s lmao I made this comment 4 years ago, glad to see people still chugging on the math train
....I like the purple. And the fact this is saving my grade.
Ur the best khan academy thank you so much
why would u ever dislike mr khan????? 58 dislikes????? why????? he's doing great
To all students, yes the y-intercept should be 6/4 (reduced to 3/2 or 1.5) for the second inequality. Other than that, his process is totally right.
Thank You! This was very helpful and I got to finish my math homework! I Liked and Subscribed.
Best Teacher ever!
Omfg thx my test is tmrw and this was super helpfull
What if you have an equation that has the y intercept bigger than the graph. For example if I have x+y is less or equal to 200 and 5x+6y is greater or equal to 500. Even if I put the equation in y=mx+b form, the y intercept is still big so how do I graph that on a graph that just the y axis goes up til 10 and how do I graph the slope?
In the second example, why is the y intercept 6, instead of 6/4 or 3/2? Both sides had to be divided by four, so that should make 6 become 6 over 4, right?
learned more in this video than my teacher teached me
Khan academy never let's me down lol I'm about to get a good grade on my test now
Wow thank u so much, I've learned more than what my teacher thought me👀
I love math but this made me want to throw hands I appreciate you so much for helping me understand this it’s fun now my teacher is doo doo water
OHHHHHHHHHHHHHH MYYYYYYYYYYYYYYYY GOOOOOOOOOOOOOOOOD thank you.!! You are the god of Algebra.!!!!!!
what program do you guys use to do the equation?
Error at 3:40. 6/4 not 6. But you still get the idea. The y intercept would be lower but same slope.
I think this man just saved my future
I'm a learned Doctor and I didn't catch the error. Its funny how many teachers are watching this video.
1:31 the point , this instantanous rate of change just illustrated how hournadous my maths is.😢😢
OOMG THANK YOU SOOO MUCH U JUST PROBABLY HELPED ME PASS MY GRADE
WOW thank you the shading part our teacher taught us was so fucking confusing, you just saved my life
no reason for the lauguage my love 🥰
Thank you. You must be an algebra god.
Hey ! I have a question. Why do we need to graph this inequality thingie in the first place?
@Brian Wang ME TOO! Thanks a lot Khan Academy.
He decided to make it happen. If he should have divided 6 by 4 the result would be 1.5 or round off 2. But maybe the y should have been between the 1 and 2. Then solve the slope.
Ur a blessing cause my teacher sucks at explaining
"When you run 3, you go up 2" what if it's not a fraction? For example: y > 4x - 7... do we run 4 and go up 1?
Short Answer: You go up 4 and over (to
the right) 1. (Explanation below)
_________________________________________
Explanation:
I personally prefer using rise over run,
which is the same method he used, but he
just flipped it (run over rise), which is more
confusing to people who don’t know how
to do it. So in your situation you can turn
the slope (rate of change), which is 4, into
4/1, since 4/1 still = 4. So then when
graphing you would start at -7 on the y-axis
AKA (0,-7), and rise (go up) 4 and over
(right) 1 and repeat. Once you run out of
room on the graph, unless you want to just
use a ruler to draw your line, which is less
accurate, you go back to the starting point
(0,-7), using the slope, and go in reverse.
Since -4/-1 also = 4, then you can start at
(0,-7) and go down 4 and over (to the left) 1
and repeat. Also, in the situation, when
connecting the points, if your line is going
downwards from the left to the right of the
graph (negative/decreasing), then it’s
wrong. Because 4 is a positive (increasing)
number so your line should go up from the
left to the right of the graph, because it’s
increasing. However, you can’t use -4/1 or
4/-1 as they both = -4 instead of 4. So using
-4 as the slope would make your line
negative/decreasing and make your graph
incorrect.
It's going to e 4/1
Does the inequalities sign change when dividing by a positive number?
just negative
i wonder what sal is doing 9 years after he made this video
thx bro dizz will really help for my test bm3 benchmark 3 for algebra
When you do the second equation you divide both sides by 4 and there is 6/4 and you say it is just 6 when you move on. Is this an error or is there a reason why you did this?
Thank you Khan Academy.
6/4 = 6
Quick mafs
3:54 how is 6/4=6 ?
The y intercept can't be a fraction
+Clorox Bleach
1.5 then
It's not
@@matthewherzeca3251 please stop saying that yes it can. You’re confusing people.
Guys 6/4 is 6. Is this a new theorem or postulate?
How do we solve a system of linear inequalities algebraically?
With systems of equations there is one set answer, but with inequalities there is not one set answer. From my knowledge the only way you can is from using sub. to plug in points for the x and y. Example y>1x+2; y1(3)+2 and the same for other inequalities. You check and see if it’s a true statement
@@maxcolburn8323 Thank you!
This dude has taught me more stuff about math than my actual math teacher. Just because he made one little mistake -you know the thing that separates humans from machines- You start criticizing him. So sad. I bet you are watching this video to get help, aren't you?
6/4 = 6 pplz fix
Han Ming yup I was saying that too
its -2/-3 smart one and negative/negative gives you a positive if you were paying attention in your math class
thank you i found this helpful
Is the 1/4 taken in the second inequality common??
I thought I was dumb, I’m glad others see the 6/4 error
You would think a big company made to help teach kids would be better about checking their content
Best part at 8:51 This is how I study everynight
subtract x from the right side, and the left side, making the problem look like x-y
I love how he didn't realize . That's me honestly.
At 1:33 why does -2/3 magically turn into positive 2/3.
u probably don't care anymore but it was -2/-3 so the negatives cancel out
why dont you devide y intercept (6) by 4 as well
Legends still watching this video
3:41 shouldn't 6/4 be 3/2, not 6? lol
I get anxious by only watching this
Why wasn’t the y-int 6/4?
Wouldn't that get really messy?
why the color orange equation swaped?
Bro teaches better than my tecaher ong the only reason I’m gonna pass
What is the value of x y? The solution?
can anyone explain to me how -2/-3 x becomes positive??? just wondering..
they are both negatives so when you divide or multiply them the negatives cancel out
there is a mistake, when he divided 6/4 and then in the next line didn't get around to doing that
Why didn't you divide 6 by 4 for they intercept?
Wait shouldn't the solution set for all three line to from 0 to -n? Where n is a constant pls I am confused:/
it would have intersected on your graph if you made the intercept 3/2 as it should have been :D
didnt switch the sign after division
My biggest problem is when the y-intercept is a fraction. That always pisses me off
how do you do this algebraically?
gn
@@nigeriawilliams972 gn
Thank you so much!!!!!
3:48, the y intercept is wrong here
Danny master 😂😂😂
3 : 55 you subtract -x only x. why you didnt subtact that other number also i meam 4y
What if y and x r by themselves
Then the slope is equal to 1 and the y intercept is the origin
Thank you!
6/4 ??? who you can get 6/4 in the second one?
Solve systems of linear inequalities by graphing
Ive been studying since 12 am n im still up studying
Error 6/4 does not become 6 in 2nd inequality
Actually so helpful lol my math teacher is shit
The amount of people here unironically saying "teached" is concerning
why is 6/4 = 6, 6/4 should be equal to 3/2.
thanks this helped out a lit
Eric buell LLLLLIIIIITTTTT FFFAAAAMMM
6/4 is not 6. I'm confused.
thanks homie
I have not seen the video but but i want to comment for time pass ha hahahahaha 🇦🇧🇨🇩🇳🇳🇫🇫🇬🇵🇴🇳🇳🇴🇽🇽🆗🆒🔡🔤🆗🆙🆙🆚🗽🏰🏯🌆🌇🌇🏥🌇🎢🏬🏬⛪🏬🏤🌇
Thank you! :))
What the f happen in 9:51
@Quanami: 6/4= 3/2, yea he messed up alrite lol
Why is it 6 shouldn't it be 3/2