Mathematics - 29 December 2007

Solve the system by addition. 3x + y = –1 9x + 3y = –3

2007-12-29 14:29:11 · 5 answers · asked by cutter1890 1

The title asks it all

2007-12-29 14:24:15 · 11 answers · asked by Anonymous

If -6(2x+1)=4x+10, than x =

Show your work

2007-12-29 13:58:35 · 20 answers · asked by innosa 2

x, y, and z are positive whole numbers

find what x, y, and z are.

1/x+1/y+1/z=5/6


Plzzz i really can't figure it out.

2007-12-29 13:55:15 · 5 answers · asked by 100%angelic 3

Machine A can do a job 12 hours and machine B can do the job in 8 hours.

If B starts 2 hours after A has started, find the total time needed for the two machines to complete the job?


Please explain >< !!!

2007-12-29 13:25:51 · 8 answers · asked by Chipee 1

I keep doing this problem and my values keep canceling themselves out? So I was wondering if this is not possible to be solved. Can you do it and tell me what you get? If you are able to solve it can you give me a quick guide on how you got to your answer, thanks!

Here it is:

2x+3y=-2
4y+2z=-10
3x+5z=1

Thanks for helping!

2007-12-29 13:17:02 · 6 answers · asked by Anonymous

2007-12-29 13:03:23 · 6 answers · asked by jessie95 1

If y^2 - 3x=7, then [d^2y]/[dx^2] =
a)-6/7y^3
b)-3/y^3
c)3
d)3/2y
e)-9/4y^3
please explain because i don't fully understand how to do this

2007-12-29 12:54:39 · 3 answers · asked by affy 2

i need the answer in Ax+By=C form.. details world hellPP..
i have three differnent answers...tell me which one is right..or iof you have a totally new one.

-3x + 2y = 6
3x - 2y = -6
-(3/2)x + y = 3

2007-12-29 12:49:27 · 7 answers · asked by th31N0nliigiRl 1

This is actually a sample GRE problem: a quantitative comparison between sqrt(79*80*81*82) and 6400. I recognized that 6400 = sqrt(80*80*80*80) and was therefore faced with comparing 79*81*82 to 80*80*80. I got the right answer, but it was only a guess on my part. So if I didn't have a calculator handy, how could I know that 79*80*81*82 was greater than 80*80*80*80?

I know that it is NOT true, for an arbitrary integer x, that (x-1)x(x+1)(x+2) > x^4. (It doesn't, for example, work for 1, or -1, or -2, or 0.)

2007-12-29 12:39:41 · 3 answers · asked by AxiomOfChoice 2

2007-12-29 12:33:17 · 8 answers · asked by Anonymous

2007-12-29 12:30:19 · 8 answers · asked by QuackAttack 1

How do I convert 530 minutes into hours and minutes? I know how it is done but I don't know how to change it from a decimal answer into hours and minutes.

2007-12-29 11:44:34 · 20 answers · asked by Corey 1

Al, Betty, and Carl can harvest a strawberry crop in 12 hours if they work together. If each person worked alone, Al could complete the job in 30 hours, and Carl would take twice as long as Betty. How long would it take Carl to do the job?

2007-12-29 11:22:12 · 6 answers · asked by 2 days after my B day :) 2

Explain.

2007-12-29 10:54:09 · 14 answers · asked by innosa 2

i Just need the answer but it would be kind to explain how you got it..

=]

2007-12-29 10:46:52 · 7 answers · asked by th31N0nliigiRl 1

1/y-1 + 2/y+1 = 0


the 1 and 2 are over the equation like a fraction

2007-12-29 10:39:18 · 3 answers · asked by Dawn 1

A point moves along a curve y=(2x^2)+1 in such a way that the y value is decreasin at the rate of 2 units per second. At what rate is x changing when x= 3/2?

2007-12-29 10:38:07 · 3 answers · asked by ashlea o 2

Checking to see if there's an error in my book:

1/2x - 3 is below or equal to 1

When I solved it, my answer came out to x is below or equal to 8. My book says the answer is 2 is below or equal to x is below or equal to 8 (2

2007-12-29 10:30:30 · 12 answers · asked by Anonymous

19.
x+y=3
2x-y=9
3x+y+2z=1

A:x=2, y=-1, z=-2

20.
2x+3y=-2
4y+2z=-10
3x+5z=1

A: not possible?

21
2x-3y-4z=-21
4x+2y-3z=-14
-3x-4y+2z=-10

A: x= -14.76, y= 9.1, z=-8.95

22.
6x-y-3z=2
-3x+y-3z=1
-2x+3y+z=-6

A: x=-2, y=-15.5, z= .5

23.
2x+y+z=4
4x+3y-2z=21
2x-2y-z=-7

A: not possible?

24.
3x+2y=z-7
5x+3y=-12+2z
2x+3y=-5+z

A: not possible?

2007-12-29 10:28:43 · 5 answers · asked by Anonymous

When the equation H2 + Fe3O4 -> Fe + H2O is completely balanced using the smallest whole numbers the coefficient of H2 would be....
A) 1
B) 3
C) 2
D) 4

2007-12-29 10:25:16 · 5 answers · asked by Anonymous

I was given this problem, and I have no clue what it means or wheere to start. The answer and how to arrive to it would be much appreciated.

Thanks

2007-12-29 10:22:48 · 6 answers · asked by frank e 1

2007-12-29 10:08:49 · 44 answers · asked by Jacob 2

If they aren't can you tell me the right answer and maybe even a short description of how you got there, thanks!

SOLVE EACH SYSTEM OF LINEAR EQUATIONS IF POSSIBLE.

2.
x=2
2x+3z=13
x-3y+z=-10

A: x=2, y=5, z=3

3.
x+z=5
-2x+y+z=-5
3x-2y-z=9

A: x=3, y=-1, z=2

4.
x-2y+3z=-3
2x-3y-z=7
3x+y-2z=6

A: x=(3/4), y=-1, z=-2

5.
x-2y+4z=-8
2x+2y-z=11
x+y-2z=10

A: x=4, y=0, z=-3

2007-12-29 10:07:49 · 12 answers · asked by Anonymous

2007-12-29 09:54:54 · 8 answers · asked by ppd232 1

An open box is to be made using cardboard 8cm by 15cm by cutting a square from each corner and folding the sides up. Find the length of a side of the square being cut so that the box will have a maximum voulme.

2007-12-29 09:53:17 · 4 answers · asked by drainbamaged303 1

5y+2 2x-4
------ + -------
xy^2 4xy


adding and subtracting rational expressions...i dont get any of this rational expresion crap...its so hard...i want to punch myself


im only in 10th grade

2007-12-29 09:45:35 · 11 answers · asked by Anonymous

2007-12-29 09:22:45 · 3 answers · asked by drainbamaged303 1

How many cups equal 122 Grams

2007-12-29 09:08:35 · 8 answers · asked by conblond2000 1

2007-12-29 09:03:00 · 4 answers · asked by ? 4