Mathematics - 9 December 2007

2x-5y=1 and -3x+7y= -3


2) What is the solution to this system of equations?
2x+y=7
3x-y=3

2007-12-09 04:52:24 · 1 answers · asked by yankeefan13x 1

A Cruise liner travels with the water current for 1000 miles. On the way to the destination, the water current helps and makes the travel time shorter. The speed of the water current is 5 miles an hour. The round trip takes 45 hours. How fast would the speed of the Cruise liner be if there was no current?

2007-12-09 04:52:12 · 1 answers · asked by Anonymous

2007-12-09 04:45:30 · 4 answers · asked by vivica 1

What makes a true mathematician?

What is the difference between someone who is good at math and a mathematician?

2007-12-09 04:33:25 · 3 answers · asked by Anonymous

Help me to find these unknown values?
1. Let p and q be real numbers and let f be the function defined by the piece function:

f(x) = 1+2p(x-1)+(x-1)^2 [x less or equal to 1]
qx+p [x greater than 1]

a. Find the values of p and q for which f is differentiable at x=1.
b. Using your values of p and q, is f" continuous?

2007-12-09 04:29:21 · 2 answers · asked by Anonymous

log(base6) 9+log (base6) 4

2007-12-09 04:19:30 · 3 answers · asked by star baller 360 5

The population of the world was about 5.3 billion in 1990. Birth rates in the 1990s ranged from 35 to 40 million per year and death rates ranged from 15 to 20 million per year. Lets assume that the carrying capacity for world population is 100 billion.

a) Write the logistic differential eq. for these data. (because the initial pop is small compared to the carrying capacity, you can take k to be an estimate of the initial relative growth rate).
b) use the logistic model to estimate the world population in the year 2000 and compare with the actual population of 6.1 billion.
c) Use the logistic model to predict the world population in the years 2100 and 2500.
d) What are your predictions if the carrying capacity is 50 billion?

show work/steps plz..thanks!

2007-12-09 04:12:15 · 1 answers · asked by Anonymous

2007-12-09 04:11:30 · 5 answers · asked by Book of Changes 3

2007-12-09 03:53:00 · 1 answers · asked by vivica 1

What is the derivative of sin(x + (π/2))

Is it: cos (x + (π/2))? Or is there a chainrule involved?

2007-12-09 03:45:47 · 5 answers · asked by Anonymous

I picked two points to hep me find the rate of change of a graph.

3,3
-3,1

What would be the rate of change?

2007-12-09 03:44:17 · 3 answers · asked by Anonymous

How to solve
lim (sinx)^x
x->0+
I know that the limit is 1 but I don't know how to come to it

2007-12-09 03:37:13 · 1 answers · asked by Anonymous

2007-12-09 03:35:51 · 2 answers · asked by Ashh 1

log(5) (x-1) + log(5) (x-2) - log(5) (x+6) = 0

**(5) means to the base of 5
** please help step by step
*** the awnser is suposed to be
x=2 + 2 [square root of 2]

2007-12-09 03:35:08 · 10 answers · asked by TurkishRose 1

I'm doing a study with two groups of individuals, one who self harm and one who do not. Within these groups people are assigned to one of two interventions at random. These individuals, at the start of the experiment, also undergo a mood manipulation (all undergo the same negative one). This is then followed by the above intervention. I'm testing mood before the mood induction, after the mood induction and after the intervention. So it goes test mood 1 - mood manipulation - test mood 2 - intervention - test mood 3.

Firstly I need to do a few comparisons. I need to compare test 1 with test 3, test 1 with test 2, and test 2 with test 3. Is a repeated-measures t test the best way to go about this, or some kind of ANOVA? (and if so, which would be recommended?)

2007-12-09 03:34:05 · 2 answers · asked by Ju C 1

Find the dimensions of a rectangle with area 27000 m2 whose perimeter is as small as possible. (Give your answers in increasing order, to the nearest meter.)

2007-12-09 03:33:23 · 2 answers · asked by beccaleigh1911 1

This is what my worksheet says:

If you were to solve the following, what would your first step be?

9) 2x-7=3
a. subtract 7
b. multiply by 2
c. divide by 2
d. add 7

10.) -4=8+(x over 4)
a. subtract 8
b. add 8
c. multiply by 4
d. add 4

11.) 2-4x= -6
a. add 2
b. subtract 2
c. divide by -4
d. add 6

12.) -5+(3 over 4 x)=1
a. multiply by (4 over 3)
b. subtract 5
c. subtract 1
d. add 5

i dont get these AT ALL. what are the answers? they dont make any sense.

2007-12-09 03:19:35 · 4 answers · asked by Anonymous

I am looking for the dimensions of a square box with a volume of 48 cubic inches and a surface area of 112 square inches.

2007-12-09 02:48:34 · 11 answers · asked by Anonymous

i know its 4/5 but how?
method please =D

2007-12-09 02:46:30 · 4 answers · asked by rogla 3

2007-12-09 02:39:11 · 5 answers · asked by wendym63 2

2 – 3[-4 + 6] ÷ (-2)

2007-12-09 02:33:15 · 9 answers · asked by laindia187 1

solve the equation

2^x = 4x

2007-12-09 01:59:45 · 4 answers · asked by elnegely 1

This is an exercise of Morandi, that i couldn't solve. I have done the rest of my homework, so please, give me some help!

Let K a field and suposse that s is an automorphism of K, and s has infinite order. Let F be the fixed field of s. If the extension K / F is algebraic, show that K is normal over F.

2007-12-09 01:58:46 · 2 answers · asked by awing82 2

basically i need to know what this is equal to:

[ (3x - 1)^1/3]^2

thanks

2007-12-09 01:51:02 · 6 answers · asked by Anonymous

Ex:square number are:

1; 2; 4 ;9 ;14 ;25; 36; 49; 64; 81...

2007-12-09 01:48:29 · 2 answers · asked by lovelystarr_86dl 1

Can you do this problem? Is it to easy or to hard? Feedback about it please, 13,14 year olds should be able to solve this.

5w - 7^2 -6(3+2) = -29 + 7½ w

Solve for W.

2007-12-09 01:38:37 · 6 answers · asked by Anonymous

were moving 25 miles away from town how many hours is that?

2007-12-09 01:32:11 · 10 answers · asked by onz 1

2007-12-09 01:20:08 · 1 answers · asked by Anonymous

the volume of paint in a rt. cylindrical can is given by V=4t^2-t where t is time in seconds and V is the volume in cbc.cm. How fast is the level rising when the height is 2cm? the can has a height of 4 cm and a radius of 2. i don't get how you are supposed to solve since the formula doesn't have h, and we need dh/dt

2007-12-09 01:00:04 · 1 answers · asked by Tim H 1

Whatever the derivative is i need to set it equal to zero to optimize it for the minimum.

2007-12-09 00:52:49 · 3 answers · asked by Anonymous