Mathematics - 18 June 2007

I dont know how to solve this word problem.....The local swimming pool has two drain valves. One valve can empty the pool in 4 hours, while the other takes 6 hours to drain the pool. How quickly can the pool be drained if both valves are opened?

can someone help me?
it would be great if you showed the steps. =]
kthnxs;;

2007-06-18 17:53:08 · 9 answers · asked by Jasmine 1

2007-06-18 17:39:21 · 2 answers · asked by wiggit17 1

the point ( 0,0) ( pi/2 , 1) and ( pi, 0)) are the graph of sin(x). to use the the qudretic formula ax^2+ bx+c and find the equation> please

2007-06-18 17:38:00 · 5 answers · asked by kareena 1

The longer sides of a parallelogram are 9 cm and 10 cm long. The longer diagonal is 15 cm. Determine the measures of the angles in the parallelogram and the length of the shorther diagonal. Thank You

2007-06-18 17:36:04 · 3 answers · asked by crobabe2182 1

Discuss a real-life situation where a straight-line graph might be applicable and explain why you think this might be true.
Think about a real-life situation that follows a linear equation, with the independent variable being years. What would the slope tell you about future years?

2007-06-18 17:32:35 · 4 answers · asked by Anonymous

2007-06-18 17:25:30 · 7 answers · asked by wiggit17 1

What is the equation of the line that contains the points with (x,y) coordinates (–3,7) and (5,–1) ?

2007-06-18 17:25:11 · 4 answers · asked by Lissa 2

int sin^2(4x)cos^2(4x) dx, int 2cos^3x dx limit from 0 to pi/4

2007-06-18 17:20:33 · 1 answers · asked by KoKo 1

int e^2x*cos(x/3)dx, int x^2lnx dx limit from 1 to e

2007-06-18 17:15:01 · 2 answers · asked by PETL 1

The sum of the digits of a two-digit number is 7 and the difference between the number and that by reversing its digits is 9. Find the number.

2007-06-18 17:11:29 · 7 answers · asked by Prithika 2

2007-06-18 17:10:12 · 3 answers · asked by Anonymous

A recent article in the Wall Street Journal reported that the 30-year mortgage rate is now less than 6 percent. A sample of eight small banks in the Midwest revealed the following 30- year rates (in percent):
4.8
5.3
6.5
4.8
6.1
5.8
6.2
5.6


At the .01 significance level, can we conclude that the 30-year mortgage rate for small banks is less than 6 percent? Estimate the p-value.

2007-06-18 17:02:41 · 2 answers · asked by Help please 1

2007-06-18 16:53:52 · 2 answers · asked by MrMonkIsMyIdol 2

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

2007-06-18 16:53:25 · 7 answers · asked by Anonymous

Solve the equation. Don't forget to first simplify each side of the equation, if possible.
x + = - x -

2/3x + 1/4 = - 1/3 x - 2/9

- 4/17

1/36

- 17/36

17/36

2007-06-18 16:47:54 · 2 answers · asked by Anonymous

please help! Im trying to figure these out but Im lost!

1. multiply. (4x-12)/(x^2+6x) times 5x/(3-x)

2. Divide. 3/x^7 divided by 6/x^3

3. Divide. (2x-6)/21 divided by (5x-15)/12

2007-06-18 16:45:45 · 8 answers · asked by Anonymous

Solve the equation.
4x - (3x - 1) = 2

1
- 1

1/7
- 1/7

2007-06-18 16:41:32 · 7 answers · asked by Anonymous

Given:
x(2y-x)²+2x²(x-2y)=

I anwsered:
=-x(x-2y)²+2x²(x-2y)
=(x-2y)[2x²-x+(x-2y)]
=x(x-2y)[2x-1+x-2y]

Where did I go wrong?

2007-06-18 16:37:48 · 3 answers · asked by Anonymous

f(x)= root (6x) – (1 / root (6x))

2007-06-18 16:32:41 · 3 answers · asked by ph103 1

a pipe having a diameter of 3 inches has a rate of flow of 9 gallons per second. Under the same conditions, how many gallons per second is the rate of flow of a pipe having a 5 inch diameter?

2007-06-18 16:20:23 · 2 answers · asked by mala 2

a certain car depreciates in value at the rate of 25% per year. if the original value of the car was $24,000 , what is the net change in the value of the car over a two-year period?

2007-06-18 16:18:50 · 5 answers · asked by mala 2

A water tank has an outside diameter of 412cm and an inside diameter of 410cm.
The internal height of the tank is 200cm and the external height is 205cm.

a. What volume of water (in cm3'square') can the tank hold when full?

b. What is the volume of material used in the tank?

2007-06-18 15:52:19 · 5 answers · asked by ebneter_chick 1

Example:
(y-x)²+2(x-y)=

work:
=-(x-y)²+2(x-y)
=-(x-y)(2x-2y)
=-2(x-y)(x-y)

What's even wrong with that?
Why is it wrong to distrubute?

2007-06-18 15:26:31 · 6 answers · asked by Anonymous

find the 5th term of (1-y)^8

what is it asking for?
is there a formula?
step by step explanations would be very helpful!

2007-06-18 15:24:07 · 5 answers · asked by Anonymous

The officer in charge of a crime scene investigation discovered a body stuffed in a freezer (where the temperature was 10oF) at 1:00 PM on Wednesday, June 13, 2007. The temperature of the corpse at that time was 40oF. The officer recalls from his forensic mathematics class that t hours after death a body has temperature T = C + (To – C)(0.97)t where C is the surrounding air temperature and To is the temperature of the body at the time of death.

____________________ 6. Assuming the temperature of the corpse at the time of death was 98.6o F, and that the corpse was immediately stuffed in the freezer upon death, what was the time of death?

2007-06-18 15:11:46 · 2 answers · asked by lilmace24 1

what does it mean the 8th term?
can someone please explain how to solve the problem?
=) thank you!

2007-06-18 15:10:57 · 3 answers · asked by Anonymous

Ex.

(y-x)²=[-(x-y)]²= ?(x-y)²

How do you know it's a positive knowing the it is even ²?

ex.2

(y-x)³=[-(x-y)]³= ?(x-y)³

How do you know it's a negative?

2007-06-18 15:02:35 · 4 answers · asked by MUKLUK 1

Given: (x-y)²-3(y-x)³=

my work: (x-y)²3(x-y)³= Note: ³ gives you a (-)'s.
1) (x-y)(3x-3y)
2) 3(x-y)(x-y)

This is completly wrong I don't get this, I need help in explain why's. Please help me, PLEASE

2007-06-18 14:58:04 · 1 answers · asked by MUKLUK 1

#1. 512 to the 1/3 power

#2. (25/64) to the -1/2 power

2007-06-18 14:56:25 · 7 answers · asked by william5000forever 2

Y= 1 OVER X-2 Give the y values for x, -1, 0, 2,3,4,

thank you

2007-06-18 14:34:24 · 3 answers · asked by quepid622 1