Mathematics - 23 July 2007

hi all!
can you please help me with some of these questions?

1. simplify (2/3)^3

2. Factorise;
x(y+2)-3(y+2)

3. i reduced a diagram on my computer using a scale factor of 80% (i.e. the linear dimensions of the diagram were reduced so that became 80% of the original dimensions). What scale factor is required to return the diagram to its original size?

thankz!

2007-07-23 23:23:35 · 5 answers · asked by i love...love 2

Show all ur working...

(a) 5x/2-9=0

(b) x^2 +12x + 3=0

2007-07-23 22:49:49 · 6 answers · asked by Anonymous

2007-07-23 22:35:47 · 10 answers · asked by ashok v 1

At a school play, adults were charged 75c and students 25c to get in and $330 was collected in total receipts. The play was held in a 600 seat auditorium which was not filled. The minimum number of adults at the play was:
a 359
b 300
c 365
d 361
e 367

2007-07-23 22:08:25 · 4 answers · asked by Anonymous

2007-07-23 22:00:39 · 7 answers · asked by ashok v 1

Find a 10 terms Taylor's series approximation to f(x) = cos x and f(x) = sin x,

I have no idea how to do this problem, can anyone help me start?

2007-07-23 21:36:37 · 2 answers · asked by superman 4

2007-07-23 20:57:53 · 1 answers · asked by starchaser18 2

Consider the initial value problem
dA/dt = kA, A(0) = A_0 (where '_' means subscript)
as the model for the decay of a radioactive substance.

(i) Show that, in general, the half-life T of the substance is
T = - ln 2 / k.
(ii) Show that the solution of the initial value problem in part (1) can be written as
A(t) = A_(0) * 2^(e*(-t / T)).
(iii) If a radioactive substance has the half-life T given in part (i), how long will it take an initial amount A_0 of the substance to decay to 1/8 A_0?

I am at a loss as to what to do for all parts of this question. If someone who knew how to do this, would maybe express their ideas (even solve the problem!!) - well that would be wonderful!!

Thank-you!

2007-07-23 20:01:19 · 3 answers · asked by David C 1

The upper right-hand corner of a piece of paper 12 by 8 is folded over to the bottom edge. How would you fold it to minimize the length of the fold? Basically, what are the dimensions of the fold. How far from the corner down, or how far from the corner to the left should the fold be made. The right corner is supposed to just touch the bottom edge.

2007-07-23 19:57:15 · 1 answers · asked by p00n 2

I don't know how to solve this problem...Thanks for the help!

2007-07-23 19:56:27 · 9 answers · asked by christopher G 1

three cards are drawn from a deck...what is the probability that u the second card is an ace without the first being showed to u

2007-07-23 19:13:03 · 5 answers · asked by ellie_2121 3

1. The area of a rhombus is 7.5 sq. in. Find the length of the two diagonals if one of them is one more than twice the other. Explain it bro.

2. Below is a square split into four rectangular parts. The areas of two of the parts are provided. The lengths of the sides are whole numbers. Find the area of the entire square. Write a clear and concise explanation to justify your answer.

http://i49.photobucket.com/albums/f283/mystalkingshadow/06_04h_06a.gif



- ya it is school work no I cannot get the first one but they still are interesting questions though

2007-07-23 18:51:49 · 4 answers · asked by Anonymous

How much is it worth when it is 10 years old?

2007-07-23 18:23:03 · 4 answers · asked by Mr. Al 2

each page of a book will contain 30in^2 of print, and each page must have 2in margins at the top and bottom of the page. and 1 in margin on the left and right.
What is the minimum possible area of such a page?

2007-07-23 18:22:37 · 4 answers · asked by jenny 1

Question:

If each group of numbers consist of 2 numbers,

the numbers may range between (1-36)

Use the following numbers to determine the next group of numbers.

If 10-19 becomes 16-12

16-12 becomes 14-19

14-19 becomes 02-34

02-34 becomes 16-34

16-34 becomes 24-23

24-23 becomes 29-34

29-34 becomes 11-03

11-03 becomes 30-30

What does 30-30 become?

2007-07-23 17:58:11 · 2 answers · asked by justin j 2

(7,3) (3,7)
y=-1x+10

why is this wrong.help me solve this.

2007-07-23 17:42:12 · 7 answers · asked by Anonymous

If n=7 and r=21, compute a 98% confidence interval for p.

2007-07-23 17:29:51 · 2 answers · asked by Anonymous

yes how do you solve this...
as in the method...

2007-07-23 17:19:15 · 11 answers · asked by Anonymous

(x-4)/(x^2-3x+2)+(x+3)/(x^2-4)

apparently, i'm really bad at simplifying...

2007-07-23 17:02:06 · 4 answers · asked by nidya 1

I have started this problem and am stuck ... this is what I have so far ...

Zeros: -3, 0, 4; degree 3

f(x)=(x+3)(x-0)(x-4)
=(x^2+3)(x-4)
=x^3-12+3x-4x^2

the answer is supposed to be:
f(x)=x^3 - x^2 - 12x for a = 1

2007-07-23 17:01:18 · 2 answers · asked by snugga_bug 1

I have the rational equation of x^2/x^3
My assignment is to change the coefficient in the numerator, change the coefficient in the denominator, and make a change in the constant.
Change in numerator was x^4/x^3
Change in the denominator was x^2/x^6
How do I change the constant? What is the constant?

2007-07-23 16:50:06 · 4 answers · asked by Anonymous

( (4ac)/b^-3 ) ^-2

the answer is 1/16a^2b^6c^2

but i can't get it, can someone explain?


also....

(2√3-√5)^2

the answer is 17-4√15


please explain! thx

2007-07-23 16:37:21 · 4 answers · asked by mystery_girl07 2

(5,5)
m=-3

is this answer correct
y=-3-30x

and help me sollve
(-1,5)
m=-1

(-1,0)
m==2

2007-07-23 16:10:31 · 9 answers · asked by yoshi_gurl08 1

I creating a anwser key for a couple worksheets. Thank you for all the help i get.

This all comes straight off the sheet.
Factor each expression. Be sure to write your answer in standard form.

1. n2 + 10n + 25 1)__________________________

2. r2 – 14r – 51 2)__________________________

3. 5x2 – 3x – 2 3)__________________________

4. 4n2 + 17n – 15 4)__________________________

5. 5x2 – 11x + 2 5) __________________________

6. 81x2 – 121 6) _________________________

7. 36t2 - 169 7) __________________________

8. 9x2 + 24x + 16 8) __________________________

9. 16x2 – 24x + 9 9) __________________________

Solve each equation by factoring. (3 points each)

10. (x + 8)(6x – 7) = 0 10) __________________________

11. 2n2 – 5n = 12 11) __________________________

12. (8y – 3)(4y + 1) = 0 12) __________________________

13. 6m2 = 13m + 28 13) __________________________

Word problems. Write your answer in simplest, standard form. ( 4 points each)

14. A rectangular sheet of paper has area 55 in.2. Its dimensions are (x + 2) in. by (x + 8) in. What are the dimensions of the sheet of paper.

14) __________________________

15. A banner is the shape of a right triangle of area 63 in.2. The height of the banner is 4 in. less than twice the width of the banner. Find the height and width of the banner.

15) __________________________

16. Suppose you are building a storage box of volume 4368 in.3. The box will be 24 in. long. The height of the box will be 1 in. more than its width. Find the height and width of the banner.

16) __________________________

2007-07-23 16:07:00 · 10 answers · asked by Allen 1

how many U.S dollars is that?

2007-07-23 16:05:48 · 9 answers · asked by Anonymous

can anyone show me how to prove -i=1/i. thanx

2007-07-23 16:04:14 · 6 answers · asked by Anonymous

How many Euros will you receive?

80 Euros

100 Euros

120 Euros

187.50 Euros

2007-07-23 16:03:17 · 7 answers · asked by miss_unique16 2

I have weight range ( in pounds ) of athletes and corresponding number of athletes in a camp in a overlapping manner

http://img522.imageshack.us/my.php?image=scan0004wg8.jpg

i want to find MINIMUM number of athletes in the camp .

please explain the logic of your answer

2007-07-23 15:42:59 · 3 answers · asked by calculus 1

2007-07-23 15:38:39 · 5 answers · asked by Martinez 1

I'm doing modular arithmetic and can't figure this out!!

2007-07-23 14:56:26 · 3 answers · asked by Anonymous