How to Solve a Linear Programming Problem using the Simplex Method

In this listen we first learn the concept of slack variables and then we learn how to solve a linear programming problem using the simplex method.

[@alinikitabar1275]

i missed this class at my university and everyone was telling me how hard it is, and u explained it beautifully thank you

[@misa3483]

This is extremely underrated. Best video on the topic. You did in 15 minutes what my teacher couldn't in 8 hours. All those little notes were extremely useful in putting things into context, I knew how to do this a little bit, but you explained every single "why" I had.

[@fmlodno1zy]

Great Video, The only one on youtube that properly explained how to solve the simplex method

[@yassine6532]

It's 2020, and I get to understand the concept perfectly. I came to learn about sensitivity analysis and I ffound myself watching all videos in the playlist because truly you well-explained all concepts. Thank you.

[@reikiyamya1912]

1 year after completing my Masters and today, I think, I fully understood the Simplex Method. Amazing explanation 🎉

[@luciathegreat5621]

Finally i got the concept. Shokoufeh you are a true hero.

[@tharock220]

Thank you so much!!! I'm taking optimization at the University of Washington right now. I think my professor is great, but this playlist made linear programming a lot easier to understand. I'm not just writing out constraints and plugging them into CVXR anymore.

[@SabbirAhmed-nc5hh]

this is the only video I've got so far that has explained the process correctly. .Thank you!

[@DigiFiveThousand]

You are a complete lifesaver, thank you so much!

[@peterquill1193]

Thank you for making those videos the entire playlist is very helpful and well explained.

[@SquareLeim]

Very nice video, helped me understand the method in time for my final!

[@PapiJack]

Great video. It would really help if you use your mouse to point at the values you are manipulating at any given time. It makes it easier to follow what you are saying. Thanks.

[@RoohaAli]

you make it so easy for me Jazaka-ALLAH

[@MrBorzoo]

Very well and thoroughly explained. Great job Shokoufeh.

[@dawidsabat200]

Great job! Your video helped a lot.

[@KoyeLadeleMosimiloluwa]

Wow! Thank you! This was really helpful!

[@PlainLazyZitu]

really really great tutorial. thank you a lot for your help.

[@muhammadfaruq6235]

Thank you, really helped me out alot..

[@ukiyo-lk8sq]

Jazakallah Mirzaei, huge respect for you. Thank u so much ❤

[@dariasmaja7118]

This is so well - explained. Thanks

[@updyfatahibrahim3521]

Perfect , simple and direct to the point thank u MS LOVE U

[@rixiejaelflorescertifico2237]

Thank you so much, you saved me, new subscriber here!!!

[@hananyisehak6693]

This is just perfect explanation!

[@elenazaimova3105]

Thanks a lot! It is a really good explanation!

[@MuhammadSalman-om4rn]

hey, thanks for sharing, it was really helpful.

[@bensonotiero9022]

Your video has been of great help..thanks alot 👊

[@karamiali]

امام علی میفرماید......"زکاة العلم نشره .......دمت گرم شکوفه جووون، استفاده بردیم از علم و سواد شما

[@GBmeme]

Speed and great explain… !✨⭐️thankyou…❤✨⭐️

[@VinodSeshadri]

Great and simple explanation...

[@talhademir3241]

thank you very much very helpfull series

[@omprakashkumawat5835]

Best video to learn LP-simplex method.

[@dilankarathnayake3785]

It gave me a good idea. Tks lot, Good job !

[@pranavrajwade3220]

Hey that was good video :) Thanks for uploading!

[@albertomatus3025]

Thanks You very much. Greetings from Chile 🇨🇱

[@Naqiibraheem]

Thank you a lot , you helped me ☺

[@almatrood100]

thank you a lot you've explained it very good :)

[@alimotawie]

thanks for your efforts making this video ,, thanks for helping other people learn

[@kkprokopton]

Hi Mirzaei, Indeed very simple and easy tutorial.

[@yahiabouda]

Thanks for the video!

[@ShishirPriyadarisi]

Awesome Video. Thanks a Lot.

[@rakeshstha7]

thanks, it was helpful

[@alainlee4938]

Hello shouldnt the z for the 2nd table x1 under x1 be 6 ?

[@BARaaz04]

Best explanation ever

[@musarurwagororo5532]

i love you! thank you so much!

[@pc50505]

superb ....... thx

[@RezaMusicy]

Hi Shokoufeh, Thanks for the video, I was wondering if the second constraint in the first iteration would be 5 + S2 or 6 + S2?

[@manaras-uh1bc]

finally a video without an indian accent

[@mogg75]

OMGGG thank you soo much

[@VishalKNair]

Thanks a lot! :)

[@danaayounus]

thank you so muchh

[@kev95singh]

Made ma day

[@Elyineify]

It IS really good ! but in the beginning I think you must have miss calculated the S value for teh second one,because if we add up the numbers of x it will be 6 and not 5, 5 is for the third one only. I dont know whether Im wrong or not... However good video !!

[@sxmirzaei]

tnx, but that's been revised by annotations on the video

[@kushsingh509]

hi.... if i had to start from a point other than the origin like we usually do in simplex, how do i construct the table . (considering we are sure that the point we will start from is a corner of the shaded region graphically or a basic feasible solution)

[@oussamamachi33]

Thank's :)

[@danielatego6086]

Thank you

[@nimamaleki1595]

Hello Ms. Mirzaei, I'm trying to get more comfortable with simplex. I perfectly understand the maximization type in this video. Previously, I thought that the only way to solve minimization problems was to use the duality property, but now I'm hearing that it is also possible without taking advantage of duality. If so, can you be so kind and tell me when applying simplex to a minimization problem, what things could or will possibly be different?

[@sxmirzaei]

+Nima Maleki when solving for a minimization problem, the only difference is that in the row of Z you choose the column associated with the most positive number as your pivot column, as oppose to the most negative in the max problem. the rest of the process is the exactly the same.

[@nimamaleki1595]

+Shokoufeh Mirzaei Thank you so much. Your videos are helping me A LOT!

[@nikhilkumarreddy354]

very good explanation. thank you so much madam.

[@lilromain101]

Great video. My question however is, after reaching the optimal condition, and testing the value for the basic variables in the objective function, what do we do in the event that the value on the RHS of z is not the value we get after testing?

[@sxmirzaei]

That means you made a mistake, go back and check your steps and solutions one more time.

[@mahtaamy8334]

Omg i can't believe if you say you r persian and i found you completely accidentally🤯😍

[@jehssingjohnson7747]

Thank you very very very very much.

[@tanmoyroy3254]

Awesome method of solving simplex. Thanks mam.

[@Shubham-cr6td]

Hello mam, I have a doubt about the maximization function Z , did you convert the maximization problem to minimization problem ? I mean z=6x1+5x2+4x3 why did you convert it into -(6x1+5x2+4x3)?

[@aaroncarter1112]

Probably too late, but it's called 'Row 0 Form' . Simplex requires that your objective function be equivalent to 0. So z=6a + 5b + 4c would be represented as z - 6a - 5b - 4c = 0

[@princesskaylabaliza3646]

How did you get 2/5R2 on the third table???

[@gulshansingla3875]

when there is any no is positive in z row and problem is of minimization of simplex method then who to solve. who to consider most negative value from z row.

[@sxmirzaei]

If you are solving for a min problem and there is no positive value in the row of Z to continue you are in the optimal table.

[@djataberk1]

Jyst perfect

[@SamN242]

What if its minimizing the objective function? Do you still pick the most negative number or is it different?

[@sxmirzaei]

you pick the most positive value in the row of Z row for a min problem, However the min test procedure don't change (i.e. pick the min value obtained by dividing the RHS by the positive values of the pivot column) Sam Nieuwhof

[@primeminister1040]

you applied ERO on different lines from differnet tables as oppose to what you did in the ERO tutorial , where you applied them on lines from the same matrix , why ?

[@tanmay094]

Can you suggest a book to go through for the above explained methods to solve the linear programming problem?

[@sxmirzaei]

Yes, my textbook : he.kendallhunt.com/product/linear-programming-introduction

[@tanmay094]

@@sxmirzaei Thanks a lot

[@nicesacbro4891]

How z row is being calculated in 4:11?

[@djapster]

i get it now. but this is still too tedious...

[@B0bi_007]

Can somebody confirm this: If I were asked to minimize a function (and not maximize like here) - could I just multiply the objective equation by (-1) and then do this method as in the video (so (-1) and the maximize it which will effectively do minimization)?

[@sxmirzaei]

yes, but in the end you need to remember the value of actual objective function is the negative of the value you found from the simplex table.

[@joseromano378]

can you help me with this i really need your help today :(( PROBLEM: The Our-Paint-Dries-Quickest (OPDQ) paint company produces two interior enamels: Quick-Dry and Super-Speedie. Both enamels are manufactured from premix silicate base and linseed oil solutions which OPDQ purchases from a number of different suppliers. Currently only two types of premix solutions are available. TYPE A contains 60% silicates and 40% linseed oil, whereas TYPE B contains 30% silicates and 70% linseed oil. TYPE A costs $.50 per gallon and TYPE B costs $.75 per gallon. If each gallon of Quick-Dry requires at least 25% silicates and 50% linseed oil, and each gallon of Super-Speedie requires at least 20% silicates but at most 50% linseed oil, how many gallons of each premix should OPDQ purchase in order to produce exactly 100 gallons of Quick-Dry and 100 gallons of Super-Speedie?

[@Shumayal]

What is the use of getting S3 = 60 when it holds no value in our objective function? (Slack and surplus variables will never be there in an objective function) So what's the meaning of that? Is it just there to make mathematical sense?

[@sxmirzaei]

S3 is the amount of extra resources that you have available from the third constraint. e.g. if constraint 3 is a labor hour constraint, and S3=60, it means you have 60 hours of labor resource that you are not using it. Now, if you are trying to improve your objective function, adding labor hour is not going to help in this case, because you are not strictly limited by it. From mathematical standpoint, given the value of X variables, it is the amount that you need to add to the right hand side of the third constraints to hold the equation 2X1+X2+2X3+S3=300 .

[@adebolaakintonde1484]

Please work on the lettering, I can nearly see it. Also the font is not readers friendly

[@minusv.singhs]

But I read somewhere that we stop when all values are either zero or NEGATIVE, not positive :( Where do we apply which?

[@sxmirzaei]

+Manasvi Singh thats for minimization, not maximization.

[@ToStand2]

+Manasvi Singh if you take the opposite of the objective function, it works too, i tried and then you'll stop with what you said

[@nabilaabrak5738]

So basically u switched from a maximisation problem to a minimisation one, cause this is what happens if u multiply your objectif function by -1, right? max Z ==> min (-Z)

[@ToStand2]

+Nabila abrak yes exactly

[@sxmirzaei]

yes, exactly.

[@LesSoleilsdePhoenix]

Good job and a sexy Persian accent! Just minor typos that you'll notice if you replay it at 1:45 and 1:50. It ought to be 6 + S2 = 360 => S2 = 354. Thanks!

[@francescariva6087]

my professor spent 3 hours teaching this...

[@husseinabed7908]

how can i contact you by skyp

[@sxmirzaei]

you can email me at [e-mail]

[@primerpy]

can't recognize your handwriting, please keep it simple

[@sohaibmirza9827]

You’re beautiful.

[@nataliecara5222]

This makes no sense at all