Mathematics - 8 July 2007

PROVE:

3 + 7 + 11 +.... +(4n - 1) = n(4n - 1)

2007-07-08 22:51:17 · 10 answers · asked by Ed G 2

question: The radius of a cylinder is increased by 15% and its height is decreased by 20%. Find the percentage change in the volume of the cylinder.

answer: ?????

2007-07-08 22:35:19 · 5 answers · asked by sguy 1

Ok, the answers I keep getting don't match what is in the back of the book, even though I've gotten all the previous questions in the book right. So obviously, one of us is wrong (probably me), so I want you guys to tell me what the answers are. Here is the question:

"Solve the following simultaneous equations using the substitution method:"

3x + 2y = 33
y = 41 - 5x

So basically, using the substitution method, I need to find the values of the variables. Can anyone tell me the answers?

2007-07-08 21:42:44 · 12 answers · asked by Anonymous

the radius to the outside edge of a circular path is 12 feet greater than the radius to the inside edge. of the folliwing, which is the closest approzimation to the positive difference, in feet, between the circumferences of the two edges of the path.

a 12
b 15
c 25
d 37
e 75

2007-07-08 21:00:49 · 11 answers · asked by [Music = love] <3 2

I am confused whether the order of a given graph G is just the same as the total number of vertices in a graph.
- Graph Theory

2007-07-08 20:54:57 · 2 answers · asked by Rhea Y 1

I have 450g of salt and flour mix. How many grams of flour should I add to reduce the percentage of salt in the mixture to 90% of what it was?
The answers are:
a) 50 b) 10 c) 30 d) 45 e) 60
Please answer "why" not just how as I am preparing for an exam and need to know how to do it in the future.
Thankyou for your help!

2007-07-08 20:53:43 · 8 answers · asked by checked.cherry 2

find the dimensions of a rectangle a with the greatest are whose perimeter is 30 feet.

2007-07-08 20:22:04 · 6 answers · asked by °†¿ÐámñéÐ?†° 2

Identify the following conic. That is, is it circle, parabola, hyperbola, or ellipse? Show why.

x^2 - 4y^2 - 4x - 24y = 48

2007-07-08 19:41:42 · 2 answers · asked by Sara 3

2007-07-08 19:24:54 · 2 answers · asked by LULU 1

can u help me about formula oh trigonometry

2007-07-08 19:22:33 · 4 answers · asked by wirods c 1

2007-07-08 19:00:23 · 2 answers · asked by LULU 1

give checks for the following two questions.

5. use logarithms and the law of tangents to solve the triangle ABC, given that a=21.46 ft, b=46.28 ft, and C=32* 28' 30"

6. use the method explained in Art. 23 to solve the triangle for which the given parts are a=27, b=21, and c=24.

2007-07-08 18:53:44 · 1 answers · asked by . 2

1. derive the identity for sin 3x in terms of sin x

2. using the double-angle formula, find sin 120*

2007-07-08 18:49:20 · 3 answers · asked by . 2

a. sin 2x=2 tan x/1+tan2 x

b. sin 2 0/ sin 0 - cos 2 0/cos 0= sec 0

c. sin (x+y) cos (x-y) +cos (x+y) sin (x-y)=sin 2x

d. cos 2x= cot2 x-1/cot2 x+1

2007-07-08 18:48:19 · 3 answers · asked by . 2

A nurse wishes to add water to 30 ounces of a 10% solution of whatever to dilute it to an 8% solution. How much water will she have to add?
x+.10(30)=.08(x+30)?
I am old an lost!!!

2007-07-08 18:39:36 · 3 answers · asked by calired67 4

2007-07-08 18:37:58 · 2 answers · asked by salvador9926 1

2007-07-08 18:34:21 · 1 answers · asked by salvador9926 1

a. 30
b. 45
c. 60

I keep getting 3 as my answer. Anyone know how to work this problem?

2007-07-08 18:24:55 · 3 answers · asked by nitesh8de 2

2007-07-08 18:21:32 · 3 answers · asked by WOMBAT, Manliness Expert 7

f(x)=√(x-1) ; g(x)=1/(x-7)

2007-07-08 18:16:42 · 2 answers · asked by Anonymous

2007-07-08 18:13:31 · 4 answers · asked by Pimpmeister 1

What is the equation of the ellipse with foci at (0,-4) and (0,4) and the sum of it's focal radii being 10?

2007-07-08 17:57:49 · 2 answers · asked by Sara 3

w * square root of 45z^5 + 7z^2 square root of 20zw^2

2007-07-08 17:53:01 · 1 answers · asked by mario b 1

You are driving on a trip of 2640 miles. You begin the trip with a full tank of gas and after traveling 420 miles, you refill the tank for $22. 91. How much should you plan to spend on gas the entire trip? please answer! thank yoU

2007-07-08 17:00:26 · 5 answers · asked by camille_carson 1

It's not as easy as it looks.

2007-07-08 16:55:22 · 16 answers · asked by R E 2

2007-07-08 16:48:53 · 16 answers · asked by Lost. at. Sea. 7

1000 students.
1. Suppose the first student goes along and opens evvery locker.
2. the second studentv goes along and shuts every other locker beginning with number 2.
3. the third student then goes along and changes the state of every third locker beginning with the number 3. (if the locker is open, the student shuts it and if it's closed the student will open it)
4. the fourth student changes the state of every fourth locker beginning with number 4.

if this continues until all 1000 students have followed the pattern with these lockers, which lockers will be open and which will be shut at the end? why?

2007-07-08 16:48:39 · 3 answers · asked by Anonymous

13x +14 = 12x -5

2007-07-08 16:43:17 · 6 answers · asked by d w 1

a chemist wants to make 2 L of an 8% acid solution by mixing a 10% acid solution and a 5 % acid solution. how many liters of the solution should the chemist use?

2007-07-08 16:27:16 · 6 answers · asked by camille_carson 1

(2/x-1) - (2-x/x)

2007-07-08 16:27:05 · 3 answers · asked by Anonymous