Mathematics - 15 October 2007

Please use the linear combination method or substitution method (would appreciate if linear combination i am having more troubles with that) to solve these problems i couldn't figure it out.. please and show a few steps of work i would greatly appreciate it. (Each comma seperates the 2 equations)

1) -3x+y=11, 5x-2y= -16

2) 3x-7y = 20 , -11x+10y = 5

3) 1/3x + y= 9, -2x+2y=-6

4) -x+5y=17, 2x-10y = -34

5) -2x+3y=20, 4x+4y = -15

2007-10-15 23:04:08 · 4 answers · asked by Anonymous

X^4 +15 = 8x^2

2007-10-15 22:14:47 · 5 answers · asked by Anonymous

Find the zeros in the polynomial function

P(x)=2x^ 4+3x^3-4x^2-3x+2

2007-10-15 21:14:54 · 3 answers · asked by K Rose 3

2007-10-15 21:12:12 · 11 answers · asked by jumba 1

also, what values of a and b give the maximum product?

2007-10-15 20:59:11 · 6 answers · asked by ac213 1

2007-10-15 20:40:35 · 5 answers · asked by Anonymous

Determine all significant features by hand and sketch a graph.

f(x)=sinx+cosx

basically, I need to find the first derivative of the function, get x-values, and determine whether increasing or decreasing. Then take a second derivative and determine whether it's concave up/down.

2007-10-15 19:51:12 · 9 answers · asked by Chris720 2

2x+1= - (x+3)

a) -4/3
B) -2
c) 4
d) 2/3

and why

2007-10-15 19:17:56 · 11 answers · asked by Anonymous

-3x^2 + 12x

2007-10-15 18:45:19 · 7 answers · asked by Mags 1

I had a math test today, and I'm not sure about this question.

x/8 + x/9 = 6

Can this be solved, and if so, what's the answer? Thanks a bunch.

2007-10-15 18:44:40 · 4 answers · asked by A T 2

2007-10-15 18:43:08 · 9 answers · asked by I luv my Haterz 3

Can you solve this?
Three men rent a hotel room. Each pays $10 for a total of $30 spent on the room. The next day the hotel owner tells the three men that they over paid for the room as it only costs $25. The three men tell the owner to give them each a dollar back and he can keep two dollars.

If you do the math, each man paid $9 a piece for the room for a total of $27. The owner kept $2 which brings the total to $29.

The question is where did the other dollar go?

2007-10-15 18:43:05 · 15 answers · asked by Anonymous

Solve

2007-10-15 18:23:45 · 11 answers · asked by emily s 1

There are 2 bottle of wine contain 800 ml each, and 2 empty glass with 300 ml capacity each, There is no instrument of measuring, How to divide the 1600 ml of wine to 4 people equally ?
Provide the steps.

2007-10-15 18:18:28 · 9 answers · asked by Isaac Proff 1

a)use regression to find a polynomial function n of degree 3 (cubic)that can be used to estimate the number of x years after 1940
b)estimate the number of people 65 years old and older in the u.s. in 2008
c)in what year were there approximatly30 million people 65 yrs and older in the u.s.
year 1940 1960 1980 1985 1995 2001
person
older than 65 years 9.0 16.7 25.5 28.4 33.8 35.3
(million)

2007-10-15 18:17:04 · 1 answers · asked by jatin b 1

We are doing direction derivatives in class and our lecturer is not really explaining much at all. I can't seem to understand how the direction vector is found at all. There is this question where the directional derivative is to be found at 1 point in the direction of another given point. I keep getting the direction vector wrong. Our lecturer didn't really clear up how the direction vector actually works and I still am not clear about it. It would be great if anyone can explain to me how the direction vector for let's say the following question is found:
Find the directional derivative of f(x,y,z)=y/(x+z) at P(2,1,-1) in the direction from P to Q(-1,2,0).
PS: I am not really sure if the direction vector is (2,1,-1)-(-1,2,0)=(3,-1,-1) or (-1,2,0)-(2,1,-1)=(-3,1,1)...HELP PLEASE!!!!

2007-10-15 17:54:30 · 2 answers · asked by Anonymous

express each ratio as unit rate:

625 miles in 9 days

116 meters in 12 seconds

176 new employees in 22 years

34 yards for 6 costumes ?

55 pages in 25 minutes

$3015 from 36 people

HELP PLEASE! I WILL DEARLY APPRECIATE IT! this is my homework & i don't get it & its due tomorrow! thanks!

2007-10-15 17:33:19 · 2 answers · asked by jmacsgirlie75 2

It says:
2y-a/3=a+3b/4

and one that says:

Two airplanes leave Dallas at the same time and fly in opposite directions. One airplane travels 80 mph faster than the other. After three hours, they are 2940 miles apart. What is the speed of each airplane?

PLEASE HELP ME!!!!!

2007-10-15 16:57:28 · 4 answers · asked by JesusFreak777 2

2x(squared)+8x+6

3x(squared)-12x+9

4x(squared)-x-14

2007-10-15 16:48:41 · 5 answers · asked by Arête 3

2007-10-15 16:42:51 · 9 answers · asked by Oscar 1

I've Already Answered the First Part Of the Question.

In this question I have already answered the "when are the roots complex part."
When I take the discriminant out of the quadratic formula and plug the formula in; I find that all discriminant results that are less than 0 result in a complex number.

But I am at a loss of how to sketch this?

Is it an odd circle shape on the complex plane or something?

2007-10-15 16:42:48 · 5 answers · asked by ? 3

I'm stuck on these problems. I know the answer. Just not how to get there. Please help!

1.) x^3 + 4x^2 - 3x - 2 = 0

2.) 16x^4 - 4x^3 - 16x^2 + x + 3 = 0

3.) 3(square root ->3x+14) = 15 - 2 | x - 2 |

WILL GIVE BEST ANSWER.

2007-10-15 16:39:09 · 1 answers · asked by charmedrules10 2

2007-10-15 16:28:07 · 3 answers · asked by houstonman20042002 1

What is the equation to get the sum of the first "n" powers of 2?

2007-10-15 16:16:55 · 1 answers · asked by Nesting 2

At a price of $p the demand x per month (in multiples of 100) for a new piece of software is given by x^2 + 2xp + 7p^2 = 1000.

Because of its popularity, the manufacturer is increasing the price at a rate of 20 cents per month. Find the corresponding rate of decrease in demand for the software when the software costs $10.

I am pretty sure the x variable is 10, like p. I used the quadratic formula to get this. I think i'm confusing some step in the middle where you need to use the product rule.

2007-10-15 16:14:27 · 2 answers · asked by wicky034 2

Help with math problem?..?
Complete the table and find the balance. A if $3500 is invested at an annual percentage rate of 3% for 10 years and compounded n times a year.
n=1,2,4,12,365
A=
*SO, the formula I think is A=p(1+r/n)nt

$3500 (1+.03-12) to the power of 10*12?...

2007-10-15 16:12:27 · 1 answers · asked by Cherryberry 1

100 x N =50

2007-10-15 16:07:24 · 6 answers · asked by ANGELEYEZZ 1

2007-10-15 15:50:53 · 13 answers · asked by Alan B 1

HELP HOW DO WE DO THIS??

2007-10-15 15:48:42 · 1 answers · asked by ANGELEYEZZ 1

2007-10-15 15:45:50 · 3 answers · asked by Rob 1