Mathematics - 11 July 2007

solving system of linear equations by eliminating please help me?!?


1) x - y - 6 = 0
2x + 3y + 3 = 0


2) x + 3y + 3 = 0
2x - 3y + 6 = 0




PLEASE HELP ME????? ANY MATH GENIUS HERE!!!!!!!!

2007-07-11 22:58:27 · 5 answers · asked by no__one 1

a parallelogram has consecutive side lengths of 9 and 7 and diagonals of integral lengths. How long are these diagonals?

2007-07-11 22:27:42 · 2 answers · asked by sunshine 1

2007-07-11 22:21:01 · 3 answers · asked by jv 1

the number of diagonals of a regular polygon is subtracted from the number of sides of the polygon, and the result is zero. what is the number of sides of this polygon?

2007-07-11 21:24:27 · 8 answers · asked by sunshine 1

Given a vector V1 (a, b) in 2d space , what is the simplest way to get unit vector V2 that is orthogonal to V1?

2007-07-11 21:12:12 · 2 answers · asked by teddy 2

two dice are rolled and the product of the two numbers that appear is calculated, what is the expected value of a roll?

2007-07-11 20:30:57 · 9 answers · asked by Anonymous

(a)When Charles's first child, John is born, Charles invested RM300 for him at 8% compound interest per annum. He continues to invest RM300 on each of John's birthday, up to and including his 18th birthday.What will be the total values of the investment on John's 18th birthday?

(b)If Charles starts his investment with RM500 instead of RM300 at the same interest rate, calculate on which birthday will the total investment be more than RM25000 for the first time.

2007-07-11 20:30:03 · 4 answers · asked by ♥JO the KrYpToN◄ 5

Between 0degrees celcius and 30degrees celcius, the volume V (in cubic centimeters) of 1 kg of water ata a temperature T is given approximately by the formula

V = 999.87 - 0.06426(T) + 0.0085043(T^2) - 0.0000679(T^3)

Find the temperature at which water has its maximum density.


I know the answer is around 3 degrees celcius just because i remember it from physics but i dont know how to get the answer using calculus (max and min values)

2007-07-11 20:27:18 · 5 answers · asked by Anonymous

17 cos (x) sin (y) =12 I am clueless I just missed this on a test and had no clue how to do it!!

2007-07-11 20:13:55 · 1 answers · asked by Anonymous

5x + 1 = 21

2007-07-11 19:56:20 · 26 answers · asked by Anonymous

1, 3, 10, 35, 126, 464, 1716.

So this is a pattern. All distinct combinations possible with one one-sided die (1), All the combinations possible with two two-sided die (11, 12, 22), All the combinations possible with three three-sided die (111, 112, 113, 122, 123, 133, 222, 223, 233, 333), and so on.

2007-07-11 19:55:17 · 3 answers · asked by Rob 2

the mean and standard deviation of a sample of wages in a group of firms are estimated at $ 10500 and 200 respectively. later, it is found that a wrong wage of $ 8000 of one person was included in the sample instead of the correct $7000.please can you be able to find
a) the correct mean wage
b)the correct standard deviation

2007-07-11 19:43:06 · 2 answers · asked by Anonymous

I need to find the volume formed by the region enclosed by:

x=3y and y^3 = x with y being greater than or equal to 0 about the y-axis.

I know I have to take the difference of the integral of 3/x from x^(1/3)

but after that, I have no idea what to do.

Similarly, I need to find the volume of the solid formed by rotating the region inside the first quadrant enclosed by:

y=x^4
y=64x


They're very frustrating because I have an idea of how to do them but, I don't really know how to apply the integrations.
AH!

2007-07-11 19:23:24 · 6 answers · asked by Anonymous

You have between 14 and 28 matchsticks. You take turns with the computer taking 1, 2, or 3 sticks. You get the first turn. How do you win?

2007-07-11 19:14:00 · 1 answers · asked by what 2

four points are chosen in a circle of a radius 1 unit.show that at least two of the points are within square root 3 of one another.

2007-07-11 18:41:23 · 3 answers · asked by Anonymous

can't figure it out? help

2007-07-11 18:27:24 · 3 answers · asked by Anonymous

Please xplain how you got your anwser. :D

2007-07-11 18:25:43 · 6 answers · asked by Anonymous

please help, it's for a math class. i have more whre this one came from. :)

2007-07-11 18:21:58 · 5 answers · asked by Anonymous

Jessica is a film producer evaluation a new film proposal by Steven, a rookie screenwriter and director. Jessica knows that the probability of a film by new screenwriter being successful is only 20% with the probability if the film being a flop being 80%. We shall assume that a successful film will earn the studio a profit of $50 million and a flop will lose $20million. 1. Construct a decision tree for this problem. Should Jessica proceed with the film?
2.Compute expected value of perfect information for film decision.?
part 2:
Jessica would like to hire film critic, Feneva to read the script and asses the film s chances of success. Feneva predict a successful film 70% of the time & correctly predict unsuccessful film 80% of the time. 1. Construct a decision tree for the whole problem, including all probabilities
and payoffs. 2. Should Jessica hire Feneva?

2007-07-11 18:13:37 · 1 answers · asked by Secret 2

By using the quadratic formula, solve:
1. x^2-2x-7=0
2. 2/3x^2+5/6x+1/2=0


Please help me out.. I have my final tomorrow and I am struggling with these problems. I have the answers, also, I just didn't know how to type them out because they have the square root sign as well and the "plus or minus" sign... Thank you so much for your help in advance.

2007-07-11 18:10:24 · 5 answers · asked by hey its me :] 3

solve using power series

2007-07-11 17:14:21 · 3 answers · asked by Angel 1

given x = y

x = y
x(squared) = y(squared)
x(squared) - x(squared) = y(squared) - x(squared)
x(x - x) = (y + x)(y - x)
x(y - x) / y - x = (y + x)(y - x) / y - x
x = y + x
x = x + x
1x = 2x

where did i go wrong? where is the flaw? because 1 definitely does not equal 2.

if u get it right, automatic best answer!!

2007-07-11 16:58:23 · 5 answers · asked by tochau 5

A curve is traced by a point P (x,y) which moves such that its distance from the point A(-1,1) is three times its distance from the point B(2,-1). Determine the equation of the curve.

2007-07-11 16:54:07 · 4 answers · asked by lets.dancex3 1

Please show working.

2007-07-11 16:52:52 · 7 answers · asked by asherspirit 1

the answer would be 1/9 (1 - (5/ rootx)) but how do we do it. im really confused in the steps..

2007-07-11 16:46:55 · 5 answers · asked by biomes 1

The volume of a sphere is V = (4/3)(pi)r^3 where the radius, r is measured in micrometers (1 micrometer = 10^-6). Find the average rate of change of V with respect to r when r changes from 5 to 8 micrometers?? Am I suppose to find the derivative then solve or solve with the original function?

2007-07-11 16:46:42 · 2 answers · asked by Anonymous

2007-07-11 16:42:36 · 7 answers · asked by :> er er. 1

Q9--------------A hen lays 3 eggs every day ,one of which hatches and produces a hen the same day.The newly formed hen can start laying eggs from the next day at the same rate as the previous hen and so on.for all the hens that are produced.the other two eggs laid by the first hen hatch on the second day and produces hens which can start laying eggs from the next(third) day at the same rate as the older hens.This process goes on and on.After how many days(minimum) are there 100 unhatched eggs.
a. 12
b. 10
c. 20
d. 6

2007-07-11 16:41:09 · 14 answers · asked by Anonymous

Indefinite integral

1) ∫ [x-3/(2x +3)^2 ] dx
2) ∫ t^2-3/-t^3 +9t + 1 dt
3) ∫ [ x+1 / √ x^2 +2x - 4 dx
4) ∫ x^2/x-1 dx
5) ∫ 2x/x-4 dx
6) ∫ e^x/1+e^x dx
7) ∫ (1/3x-1 - 1/3x+1) dx
8) ∫ (1 + 2x^2)^2 dx
9) ∫ x (1 + 1/x)^3 dx
10 ∫ x cos 2 pi x^2 dx

2007-07-11 16:40:26 · 1 answers · asked by Cantthinkofanickname 1

A. 3 and 4
B. 4 and 6
C. 4 and 9
D. 4.7 and 5.7
E. 8 and 27

correct answer with explanation will be chosen as best answer!

2007-07-11 16:39:55 · 5 answers · asked by Moohlah. 2