Can someone please put this [math] problem into English?

BarTopDancer · 03-05-2005, 05:26 PM

Alright,

Most of you know I hate math. I've been plodding along through this class now, getting parts of it, bsing through others. But this I am just not getting. The book, the program and the tutors all explain it the same way and it's not clicking.

It's solving ordered triples (that's what the book calls it).

6x - y + z = -24 ~~~ (eq 1)
3x + 2y - 3z = -13 ~~~ (eq 2)
x - 3y + 2z = -5 ~~~~ (eq 3)

This is what I have been doing:

I solve Eq. 1 and 2, then 1 & 3 then 4 & 5 using the elimation method. No matter what I do, even if the answers I come up with are right the program says they are wrong.

Does anyone have any tips or can they explain how to do this a differnet way?

Ghoulish Delight · 03-05-2005, 05:55 PM

[if the following is what you mean by "elimiation method" I appologize for repeating this]
The easiest way to do these is to multiply both sides of one of the equations so you can add it to or subtract it from one of the others. For instance:

Multipy eq2 by 2 to get 6x+4y-6z=-26

Now you can doe eq2 - eq1 which gives you 5y-7z=-2

Now, multiply eq3 by 6 and do eq1 - eq3. That gives you:

17y-11z=6

Now you have 2 equations and 2 variables. Solve those for y and z. Use those results to get x.

BarTopDancer · 03-05-2005, 06:04 PM

That is what I am talking about. Everything I am reading says you have to solve the 3 equations then the two new ones created by solving the other 3. Do you have to do it that way? Spending 30 minutes on a problem to end up with the wrong answer is pretty frustrating.

Cadaverous Pallor · 03-05-2005, 06:17 PM

GD says that really is the only way to do it. We're about to go out, so can't help you any more tonight...here's the answer.

Spoiler:

Stan4dSteph · 03-07-2005, 07:55 AM

You can check your answers by plugging the solutions back into the equations. If they don't check, go back and double check your solution. Chances are you added or subtracted something incorrectly along the way.

Tramspotter · 03-08-2005, 09:42 PM

No, no, no, the answer is 42

Now where did I put my towel?

03-05-2005, 05:26 PM	#1
BarTopDancer Prepping... Join Date: Jan 2005 Location: Here, there, everywhere Posts: 11,405	Can someone please put this [math] problem into English? Alright, Most of you know I hate math. I've been plodding along through this class now, getting parts of it, bsing through others. But this I am just not getting. The book, the program and the tutors all explain it the same way and it's not clicking. It's solving ordered triples (that's what the book calls it). 6x - y + z = -24 ~~~ (eq 1) 3x + 2y - 3z = -13 ~~~ (eq 2) x - 3y + 2z = -5 ~~~~ (eq 3) This is what I have been doing: I solve Eq. 1 and 2, then 1 & 3 then 4 & 5 using the elimation method. No matter what I do, even if the answers I come up with are right the program says they are wrong. Does anyone have any tips or can they explain how to do this a differnet way? __________________ Spork is the new MacGyver Postcards From My Edge
	Submit to Quotes

03-05-2005, 05:55 PM	#2
Ghoulish Delight I Floop the Pig Join Date: Jan 2005 Location: Alternative Swankstyle Posts: 19,348	[if the following is what you mean by "elimiation method" I appologize for repeating this] The easiest way to do these is to multiply both sides of one of the equations so you can add it to or subtract it from one of the others. For instance: Multipy eq2 by 2 to get 6x+4y-6z=-26 Now you can doe eq2 - eq1 which gives you 5y-7z=-2 Now, multiply eq3 by 6 and do eq1 - eq3. That gives you: 17y-11z=6 Now you have 2 equations and 2 variables. Solve those for y and z. Use those results to get x. __________________ 'He who receives an idea from me, receives instruction himself without lessening mine; as he who lights his taper at mine, receives light without darkening me.' -TJ
	Submit to Quotes

03-05-2005, 06:04 PM	#3
BarTopDancer Prepping... Join Date: Jan 2005 Location: Here, there, everywhere Posts: 11,405	That is what I am talking about. Everything I am reading says you have to solve the 3 equations then the two new ones created by solving the other 3. Do you have to do it that way? Spending 30 minutes on a problem to end up with the wrong answer is pretty frustrating. __________________ Spork is the new MacGyver Postcards From My Edge
	Submit to Quotes

03-05-2005, 06:17 PM	#4
Cadaverous Pallor ohhhh baby Join Date: Jan 2005 Location: Parental Bliss Posts: 12,364	GD says that really is the only way to do it. We're about to go out, so can't help you any more tonight...here's the answer. Spoiler: x = -4 y = 1 z = 1 __________________ The second star to the right shines in the night for you
	Submit to Quotes

03-07-2005, 07:55 AM	#5
Stan4dSteph Senior Member Join Date: Jan 2005 Location: East Bay Area, CA Posts: 3,156	You can check your answers by plugging the solutions back into the equations. If they don't check, go back and double check your solution. Chances are you added or subtracted something incorrectly along the way.
	Submit to Quotes

03-08-2005, 09:42 PM	#6
Tramspotter Show me on the bear. Join Date: Jan 2005 Location: LA Posts: 445	No, no, no, the answer is 42 Now where did I put my towel?
	Submit to Quotes