Algebra help again!

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brtspears2

Diamond Member
Nov 16, 2000
8,659
1
81
You could do it another fun way and put it into a matrix, and reduce the matrix to row-echelon form (hint, Ti-85 and up can do this for you.....)

For example you got ...
[ 2 3 7
6 -2 10]

reduce the matrix you get ...

[1 3/2 7/2
0 1 1]

From this you can tell that y =1, and you plug y into the new working equation ... 1x + 3/2y = 7/2 , solve for x, you get 2.

x=2, y=1

EDIT: I wouldnt suggest to do it this way, but its possible, and its tons of fun trying to do a large system of equations
 

BruinEd03

Platinum Member
Feb 5, 2001
2,399
1
0
Originally posted by: kehi
2x + 3y = 7
6x - 2y = 10



(-3)2x + 3y=7
+ 6x - 2y=10
------------------------
y=17 (because -6x cancels 6x)



(original equation) 2x + 3y=7

2x + 3(17)=7
2x +51 = 7
2x= -44
x= -22


Does this help?

I'm gonna have a prediction for you. You're gonna be one of those kids that get a B- on the exam, when he should have received a B+/A- because he lost points for stupid/careless mistakes. I'll let you figure out where u went wrong this time ;)

-Ed
 

Sid59

Lifer
Sep 2, 2002
11,879
3
81
Originally posted by: BruinEd03
Originally posted by: kehi
2x + 3y = 7
6x - 2y = 10



(-3)2x + 3y=7
+ 6x - 2y=10
------------------------
y=17 (because -6x cancels 6x)



(original equation) 2x + 3y=7

2x + 3(17)=7
2x +51 = 7
2x= -44
x= -22


Does this help?

I'm gonna have a prediction for you. You're gonna be one of those kids that get a B- on the exam, when he should have received a B+/A- because he lost points for stupid/careless mistakes. I'll let you figure out where u went wrong this time ;)

-Ed

lol ..
 

Nocturnal

Lifer
Jan 8, 2002
18,927
0
76
Originally posted by: Ender
We do that in grade 11 math =/ simple stuff too.

And? What's your point? You thread crapper. If you don't have nothing productive to say stay the fvck out of my thread.
 

Nocturnal

Lifer
Jan 8, 2002
18,927
0
76
Originally posted by: Ameesh
what grade are you in?

Soph in comm college taking Math 24 which is elementary algebra. Who gives a fvck though if I don't or can't solve these types of problems. Not everyone is gifted as you are. So why hate? At least I'm trying to get my education and higher it, right?
 

BruinEd03

Platinum Member
Feb 5, 2001
2,399
1
0
Originally posted by: Nocturnal
Originally posted by: Ameesh
what grade are you in?

Soph in comm college taking Math 24 which is elementary algebra. Who gives a fvck though if I don't or can't solve these types of problems. Not everyone is gifted as you are. So why hate? At least I'm trying to get my education and higher it, right?

well u should care if u can't...that isn't to mean that u should care because you would feel inferior that others have already learned this before you, but u should care because you should want to learn.

-Ed
 

Nocturnal

Lifer
Jan 8, 2002
18,927
0
76
Originally posted by: BruinEd03
Originally posted by: Nocturnal
Originally posted by: Ameesh
what grade are you in?

Soph in comm college taking Math 24 which is elementary algebra. Who gives a fvck though if I don't or can't solve these types of problems. Not everyone is gifted as you are. So why hate? At least I'm trying to get my education and higher it, right?

well u should care if u can't...that isn't to mean that u should care because you would feel inferior that others have already learned this before you, but u should care because you should want to learn.

-Ed

I do care, hence I'm taking the class. If I didn't care I wouldn't be taking the class, right?

I just hate it when you come on here looking for help and people want to criticize you because you don't know differential equations. But I guess thats the life of a nerd, he is behind the computer screen, he can do whatever he wants. Oh well!!!!

Hate on me, but at least I'm furthering my education. I'm not a drop out from high school who stayed online all night playing CS or Doom like some of you did.
 

Sid59

Lifer
Sep 2, 2002
11,879
3
81
Originally posted by: Nocturnal
Originally posted by: Ameesh
what grade are you in?

Soph in comm college taking Math 24 which is elementary algebra. Who gives a fvck though if I don't or can't solve these types of problems. Not everyone is gifted as you are. So why hate? At least I'm trying to get my education and higher it, right?

my best friend is in the same boat. He doesn't function with math. He's taken the class so many times and dropped out. He needs to get in gear. I commend you for sticking with it.
 

Nocturnal

Lifer
Jan 8, 2002
18,927
0
76
I can do it, I can do anything. I mean I'm not stupid, it's just that I am extremely lazy. Also, if you never asked for help I also commend you, but others, the majority of people, ask for help because they don't understand it.
 

Pilsnerpete

Platinum Member
Apr 4, 2002
2,060
0
0
I always ask for help even if ppl think I'm stupid. If I can learn something a little quicker, cool. If you can't deal with questions, don't hire me. And laughing and pointing won't get you anywhere.
AlgeBRA has always been fun for me.

-->Pete
 

Nocturnal

Lifer
Jan 8, 2002
18,927
0
76
Originally posted by: HonkeyDonk
Differential equations is one thing....simple simple easy ass algebra is another.

Like I said, I could do it and that's that. I just need to learn like all of you have learned what to do and how to do it.

Internet keyboard warriors rule anyhow.
 

BruinEd03

Platinum Member
Feb 5, 2001
2,399
1
0
Originally posted by: HonkeyDonk
Differential equations is one thing....simple simple easy ass algebra is another.

dude...don't hate on him. At least he's trying to better himself, which is more than you can say about a LOT of people.

-Ed
 

Ameesh

Lifer
Apr 3, 2001
23,686
1
0
Originally posted by: Nocturnal
Originally posted by: Ameesh
what grade are you in?

Soph in comm college taking Math 24 which is elementary algebra. Who gives a fvck though if I don't or can't solve these types of problems. Not everyone is gifted as you are. So why hate? At least I'm trying to get my education and higher it, right?

you neeed to chill, i was just curious, i wasn't hating on you.
 

HonkeyDonk

Diamond Member
Oct 14, 2001
4,020
0
0
Originally posted by: BruinEd03
Originally posted by: HonkeyDonk
Differential equations is one thing....simple simple easy ass algebra is another.

dude...don't hate on him. At least he's trying to better himself, which is more than you can say about a LOT of people.

-Ed

true, but when he starts snappin' at people for asking non-intrusive questions, then I have no respect for him.
 

BruinEd03

Platinum Member
Feb 5, 2001
2,399
1
0
Originally posted by: HonkeyDonk
Originally posted by: BruinEd03
Originally posted by: HonkeyDonk
Differential equations is one thing....simple simple easy ass algebra is another.

dude...don't hate on him. At least he's trying to better himself, which is more than you can say about a LOT of people.

-Ed

true, but when he starts snappin' at people for asking non-intrusive questions, then I have no respect for him.

take a look at your tone of voice...rather condescending. Even if you have the best intentions you have to admit that's a little suspect.

-Ed
 

silverpig

Lifer
Jul 29, 2001
27,703
12
81
A bit of help for Nocturnal:

When they give you a system of equations, think of each equation as telling you something about how the variables relate. The first equation gives a relationship between x and y, and so does the second. You must use both in order solve the system. That is why you can't solve the first equation for a variable and plug it back into the first equation. You'll always end up with y = y or 1 = 1 if you do that.

Also, a simpler way of thinking about it is this: They gave you 2 equations for a reason. You'll probably have to use both somehow.
 

silverpig

Lifer
Jul 29, 2001
27,703
12
81
Oh, after re-reading your first post:

You can solve for whichever variable you like. It doesn't matter whether you choose x or y. Pick whichever seems easiest.

In fact you don't even have to solve for y = something or x = something if you don't want to. If you have:

3x + 2 = 4y
3x = 2y + 2

You can just solve the first one for 3x and then equate them

3x = 4y -2

Then, because 3x = 3x, 2y +2 = 4y - 2

4 = 2y

y = 2

:)