Solving a Linear System of Equations by Graphing

[needsmetal]

what if you 3x-y=2 and 1/3y=-2+3x

[xF3ARL3SSx43VR]

That was somewhat helpful.

[patrickJMT]

@xF3ARL3SSx43VR just like your comment!

[xxhailybabexx]

if only you sat next to me during my algebra end of course...

[MrAlan1206]

U saved my life

[IFightPriests]

Thanks dude! I'm pretty sure you hear this a bunch of times but my teacher sucks balls and you are awesome

[fawkyeww11]

this is so help ful thank u very much

[aussienerds]

I HATE linear graphing. IT MAKE NO SENT! I can do equations if I am shown how. But I don't see how the numbers and variables can really make sense when calculating the gradients and stuff. This stuff's craziness!

[AtomicConnor]

internet stranger > textbook

[yesterdaywasADTR]

THANK YOU OMG

[Chicago4551]

@patrickJMT Do I use this same method if there is a number in front of Y?

[patrickJMT]

@Chicago4551 sure

[littlemissrandome1]

i thought you used rise over run for stuff like this!

am i wrong? :(

[patrickJMT]

@littlemissrandome1 that also works.

[Preciouz913]

Thank you so much! I've been going crazy all day trying to figure this out and now I finally understood it! :)

[KoreyMotherEfinDavis]

<3



[ImpGaming1]

THNX A BUNCH!!!! mist a day of math and this got me all caught up! :D

[superchaser3]

how do you work a problem like this when you have large numbers that aren't included on the graph itself, like if you have a graph where both the x axis and the y axis only go to 10, how do you work it with say, 2x + y = 3 and 7x + 5y = 21, how would you work that? Please answer, thanks in advance.

[DrunkSquirrlz]

i love you vids man

[mskennedynicole]

what would you do if the y had a number next to it ?

[SuperBafiaBoy]

@mskennedynicole When you are putting the equation into (mx+b) format, you divide by the number in front of "Y" to get it alone on the "Y" side.

[52494Princess]

Great Video! Thank you so much! Please keep posting!! :D

[dankymcdunker]

You could've explained where (2.4) came from. I finally figured it out after pondering it for a while. Where as you could've explained that very quickly and have saved me the frustration.

[SuperBafiaBoy]

@dankymcdunker It is where the two lines intersect/cross. he said it like 3 times.

[VanillaBlondie15]

Dude I'm like freakin inlove with you !!! Thank you SOOO much !! But I have one question : if it's so simple to solve the equation , then why were you guessing in the behind of the vid ?

[LovecanbeEvol]

Thank you so much! My algebra book only showed it graphed and didn't explain how to do it! I understand how to do it because of you :) thanks alot!

[menick595]

what do i do when i have 2y

[patrickJMT]

@menick595 2y is not an equation, so i am not sure what you do with it

[90jaredk]

Thanks!  You make graphing so much easier, the book examples make no sense at all.

[RobellionXD]

how did u get (2,4) ? :P

[sk8mafiay8]

This is so helpful dude!!!!!!

I had to present a project and i used this as my main math problem

it is really helpful

this is the only video that actually tells all of the stepsss

[ladyannabug]

If you have a Mac Maple is an awesome program (though it is pricey) I don't know what you could use for a windows

[ilovmc]

First 100% ever! tnx so much

[MArioLugiForTheWin]

Thank you very much sir i appreciate you for taking the time to do this. Helped so much with an upcoming test!!!!!!!!!!!!!!!!!!!!!!!!!!

[PainBringer6]

thx man i couldnt find this stuff even in my algebra book. i almost ripped my math homework to shreds and blamed it on my sister :)

[patrickJMT]

@PainBringer6 ha, be nice to your sister

[thegreasytoothpick]

Thanks...I almost threw my math book into the fireplace.

[youngreckless97]

thnx soooooooooooooooooooooooooooo much it took me 2 weeks to understand graphing but yuh helped me learn in 5 minutes lol

[itsdasupermario]

thanks dude you hept me alot

[LuckyGirl931]

How would you solve,

DIRECTIONS:Decide wether the orderd pair is a solution of the system of linear equations.

Oderd Pair: (-2,4)

4x+y=-4

All I no so far is 4(-2)+4=-4

PLZ HELP ME!!!! :(

[sallysue98t]

@LuckyGirl931 okay your on the right track no worries! lol since you have 4(-2)+4=-4........all you do is solve 4(-2)which= -8 so -8+4=-4 :) there was nuthin to it lol

[IzzyHeartsTrivium]

I love how you make these lessons clear and straight forward. Thankyou. I just coulden't help that you use a lot of paper. Grrrrr. >=( Haha.

[squinkgrl]

THNX SOOO MUCH!!! i get it for onceee!!!

[TeamWayfarer]

I hate bad college textbooks that don't explain anything but cost an arm. I love great YouTube videos that explain everything in clear terms and cost nothing. <3

[PainBringer6]

@TeamWayfarer totally. i use an algebra book and it tells me nothing, yet this video let me finish my math homework. youtube is great

[brunettehaley]

what if your equations are the same when you put them in y=mx+b like with this set

3=4y+x

4y=-x+3

[BieberrFeverrr]

if i had to solve for y, then would i use elimination or substitution, or what?? im sooo confused about it! :D

[patrickJMT]

@BieberrFeverrr you could use either method; both produce the same answer so take your pick

[BieberrFeverrr]

@patrickJMT

ohh thank you so much! :) you're an angel!!!!

[fupamaster22]

Thanks Patrick! This is probably the 4th video I have watched by you and all of them have helped very much. Keep up the good work, I'll keep watching!

[patrickJMT]

@fupamaster22 i hope you find them all useful. now go watch all 720 of the others!

[jibbinjohn]

@patrickJMT patrick im still confused help me i think im just being slow!

[comatarmsFTW]

wished u had this 1 month ago XD

[Roywood1]

Can you post a vid on how to solve systems of linear differential equations using jordan normal form? More specifically though would be when the matrix isn't easily put into jordan normal form (as in you cant easily find M for A=MJM^-1)

[Dice3000]

you can't solve more than 2 equations on a piece of paper... this method is useless really

[patrickJMT]

being able to find a geometrical connection is never useless, imo at least.

i would argue that it is, in fact, super useful

[Dice3000]

@patrickJMT ofcourse you could solve a system of 3 equations in a 3D space but that would be a waste of time. How do you solve 3+ equations using this method ?

For linear equations Gauss method is the best imo.

[Phibins]

PATRICK! i love your video's your great...

but please, please, PLEASE!!! post a video on limits based on the epsilon-delta definition.... CUZ THAT BITCH BE CRAZY!!!!!

[patrickJMT]

yo g slice

that is why i have not done it yet

everyone will give me one star, cause it is just so off the hook

[pabloMTv]

dang dawg u just dropped it like its hot

[bdub24j]

Even though I'm done with my Algebra, I like checking out your videos as a sort of refresher. Not to mention the fact they helped me through the course by making sense of the class/book explanations.

[dudemanpp]

Very nice explanation, as always. Keep up the awesome work Patrick.

[TheDuskMar]

There's three, right?

Matrices, Substitution, and Graphing?

[patrickJMT]

ya, elimination by addition (which is in essence, the matrix idea)

[thefringthing]

Remember that matrices can do a lot more than just hold some linear equations. The particular algorithm for solving these systems with matrices is called Gaussian Elimination.

[keanoscarermitano619]

I didn't get 2:18 where you put "y" to both sides. I wonder why you put "y" on both sides?

[numba1playa232]

He put "y on both sides" so he could get y on the other side of the equation to isolate it. He added y to both sides so the y on the left would cancel out to 0 and there would be a +y on the right. He most likely moved the y instead of the 5x so he could keep y positive and not have to multiply the entire equation by -1 to get +y = 5x-6 at the end.

[patrickJMT]

yep, thanks numba! could not have said it better

[numba1playa232]

you're welcome, keep up the good work.

[pitchwest]

I thought 5x would go across x not up y?

[patrickJMT]

well, a line with positive slope (that is , the line with equation y = 5x - 6) has a slope of 5. a line with positive slope goes up and you move left to right

[pitchwest]

@patrickJMT sweet thanks

[Cathode0]

@pitchwest yeah, always just think that for slope, it's "Rise / Run" or "Rise over run" or "y / x"... maybe they should be delta y and delta x for that last pneumonic. So rise refers to the y-axis and run refers to the x axis.