#1

Alright, so I'm having some trouble solving this group of equations. I'm not going to go into detail on exactly how your supposed to do it, so whoever can help me hopefully knows. Anyway, I can't get the right answer for the soluton. When I tried solving it, I got:

x = 5

y = (-4)

z = (-4)

But when I plug those back into each equation, it doesn't work out, so i'm a bit stumped. Here's the equations:

x+y+z = 3

2x-3y+z = 9

4x-5y+2z = 16

Little help from anybody?

Thanks.

x = 5

y = (-4)

z = (-4)

But when I plug those back into each equation, it doesn't work out, so i'm a bit stumped. Here's the equations:

x+y+z = 3

2x-3y+z = 9

4x-5y+2z = 16

Little help from anybody?

Thanks.

#2

youre gonna have to create a system of equations and combine and use substitution to figure that out...

#3

^what he said.

If you haven't already got it, 2x-3y=z.

I don't feel like doing any more. I had today off school and I'm not going to occupy any of it with schoolwork.

If you haven't already got it, 2x-3y=z.

I don't feel like doing any more. I had today off school and I'm not going to occupy any of it with schoolwork.

#4

MATRICIES ARE YOUR FRIEND!!!! (sp?)

A V B

|1 1 1| |X| | 3 |

|2 3 1| X |Y| = | 9 | to solve for V you put A^-1 X B= V

|4 5 2| |Z| |16|

plug into calc. you get:

| 2 |

| 2 | which means X=2 Y=2 Z=-1

|-1 |

yes, i know im a genious, than you g'day.

EDIT: wow it got really messy when it took away all the extra spaces when i posted, ubt in short

X=2

Y=2

Z=-1

plug it in and check, i didnt.

A V B

|1 1 1| |X| | 3 |

|2 3 1| X |Y| = | 9 | to solve for V you put A^-1 X B= V

|4 5 2| |Z| |16|

plug into calc. you get:

| 2 |

| 2 | which means X=2 Y=2 Z=-1

|-1 |

yes, i know im a genious, than you g'day.

EDIT: wow it got really messy when it took away all the extra spaces when i posted, ubt in short

X=2

Y=2

Z=-1

plug it in and check, i didnt.

#5

(1) x+y+z = 3

(2) 2x-3y+z = 9

(3) 4x-5y+2z = 16

(1) z = 3 - y - x

(2) 2x - 3y + 3 - y - x = 9

x - 4y = 6

x = 6 + 4y

(3) 4(6 + 4y) - 5y + 2(3 - y - 6 - 4y) = 16

24 + 4y - 5y + 6 - 2y - 12 + 4y = 16

18 + y = 16

**y = -2**

x = 6 + 4(-2)

**x = -2**

z = 3 - y - x

z = 3 - (-2) - (-2)

**z = 7**

ed: Good job, "matrix man"

#6

(1) z = 3 - y - x

(2) 2x - 3y + 3 - y - x = 9

x - 4y = 6

x = 6 + 4y

(3) 4(6 + 4y) - 5y + 2(3 - y - 6 - 4y) = 16

24 + 4y - 5y + 6 - 2y - 12 + 4y = 16

18 + y = 16y = -2

x = 6 + 4(-2)x = -2

z = 3 - y - x

z = 3 - (-2) - (-2)z = 7

ed: Good job, "matrix man"

Matricies are easier and not so............. brain hurt-y.

#7

the music man just got his as

**s**kicked...jammoe is correct
#8

the music man just got his asskicked...jammoe is correct

what, no i didnt.

plug it in and check.

X= 2

Y= 2

Z= -1

#9

Well I could use a calculator to solve it and give you the answers..but i will do it by hand anyway.

That should be the right answer. If it isn't, then I have phailed at life because I can't even do high school maths properly.

EDIT: Indeed I do phail at life, my calculator gives me a different answer..and the calculator is quite often correct. I probably made a minor mistake somewhere. No one point it out, spare me the embarassment.

That should be the right answer. If it isn't, then I have phailed at life because I can't even do high school maths properly.

EDIT: Indeed I do phail at life, my calculator gives me a different answer..and the calculator is quite often correct. I probably made a minor mistake somewhere. No one point it out, spare me the embarassment.

#10

Dood Im Right Plug It In!

#11

Dood Im Right Plug It In!

no, you're not. thats a minus 5y in the last equation not plus 5y.....

#12

Ohhh!!!!

damnit

sorry guys, simple mistake.

Edit: the martix thing still works.........but...........i dont want to plug it in my calc. again, i think the other guys right.

damnit

sorry guys, simple mistake.

Edit: the martix thing still works.........but...........i dont want to plug it in my calc. again, i think the other guys right.

#13

x=-2

y=-2

z=7

Questions, et cetera, IM me at kahn183 or zeychin on AIM.

y=-2

z=7

Questions, et cetera, IM me at kahn183 or zeychin on AIM.

#14

I'll teach you how to use Reduced Row Echelon form and solve it in a couple of minutes.

#15

Echelon form is really confusing to me.