Mathematics - 7 August 2007

if a clean up crew reduces pollutants at 8% a week, how long until only 1/5 th of the original concentration remains??

I believe the half-life is 70/.08 = 8.75 weeks

I can't figure out the time!!?? PLEASE HELP ME


Thanks so much :)

2007-08-07 16:50:18 · 5 answers · asked by princesssweetsarah 1

Today in math we were asked this question

What is the sum of the first 300 odd numbers?

He said that there is an easier way to find the answer besides having to add it one by one on the calculator. Does anyone know how to get the answer?

I'm not here so you guys can do my homework, I seriously don't know how I could do this.

Please help

2007-08-07 16:24:55 · 2 answers · asked by Julia 5

Please help. Can't start it

2007-08-07 16:04:40 · 2 answers · asked by Marvin 1

Find the inverse function of y=square root of 3x+1/7

That is the square root of 3x+1 and not of the fraction 3x+1/7

2007-08-07 15:44:57 · 4 answers · asked by Nicolás R 1

I know it is a silly question- but I am having a debate with my friend- I swear my 4th grade teacher told me this- however I attended the 4th grade many years ago...I couldn't find anything in Wikipedia...HELP!

2007-08-07 15:22:59 · 4 answers · asked by rlbaker319 1

The one that was written by Isac Newton. I am a 12th grader, and considering a major in physics.

2007-08-07 14:56:18 · 4 answers · asked by zheng89120 2

2007-08-07 14:41:26 · 11 answers · asked by Anonymous

i totally forgot how to solve this

When the number w is multiplied by 4, the result is the same as when 4 is added to w. What is the value of 3w?

2007-08-07 14:38:05 · 10 answers · asked by mxm36 1

2007-08-07 14:23:28 · 4 answers · asked by Anonymous

Please account for these factors:

1. The radius of the earth is less at the poles.

2. The flattening effect of the earth's rotational spin also makes the earth's surface at the poles flatter resulting in a horizon further away.

3. The refraction of light through the earth's atmosphere allows me to see slightly below the geometric edge of the horizon.

4. You are not directly above the North Pole, you are actually a short distance away. What is the maximum distance from the North Pole you can be (at an altitude of 10,000 meters) and still see it? This will not be the exact same number as if you were above the pole since the flattest part of the planet is on the horizon, not straight down.

I was in an airplane which flew nearly over the north pole, but not quite. I found out when the plane was at it's closest point, pointed my camera out the window due north, and took a few shots. I simply want to find out if I have a picture of the north pole or not!

2007-08-07 14:12:14 · 4 answers · asked by EdDow 1

number. Then subtract your oringinal number. Did you reach 1 for an answer? ( Redo the number game using a variable instead of an actual number and rewrite the problem as on rationalexpression). How did the number game use the skill of simplifying rational expressions? Create your own number game using the rules of algebra in order for someone to solve. Explain whether your number games uses the skill of simplifying rational expressions.

2007-08-07 14:00:37 · 2 answers · asked by Anonymous

This is kind of like a word problem, I need to find the maximum amount of area for back yard, which has a rectangular outline (fence) except it only has 3 sides (i.e. 4th side is the house)

The question tells me to complete the square to find the maximum amount of area
x is the longer side
and y is the shorter (there are 2 ys)
I'm not sure which equation you would use when completing the square and how the equation shows u the maximum area =\
I know the answer, I just need to know how to get it
x = 50
y = 25

2007-08-07 13:57:02 · 2 answers · asked by Anonymous

How do you calculate the nth root of a negative numer. i.e. 8th root of -16

2007-08-07 13:55:43 · 5 answers · asked by Yorkie1961 2

The lateral area of a rectangular prism with height of 4 feet is 60 ft2. What is the perimeter of the base?

2007-08-07 13:55:19 · 2 answers · asked by Adrienne W 1

Find the lateral area of a triangular prism with base edges of 3 cm, 4 cm, and 5 cm. Its height is 10 cm.

2007-08-07 13:53:25 · 4 answers · asked by Adrienne W 1

Find the lateral area of a square prism with edges of 14 in.

2007-08-07 13:53:10 · 1 answers · asked by Adrienne W 1

area of the sidewalk if it is 1 meter wide?
i think i have the right answer i just want to be sure

2007-08-07 13:46:08 · 5 answers · asked by Anonymous

Use three or more sentences to describe how you identify whether or not a polynomial is a difference of two squares. Then, factor the polynomial 4x2-36.

Use three or more sentences to describe how you identify whether or not a polynomial is a perfect square trinomial. Then, factor the polynomial x2-40x+400.

Consider the factoring process that has been illustrated below. Use three or more sentences to describe the process used to factor this polynomial.

3y3+4y2-12y-16
=y2(3y+4)-4(3y+4)
=(3y+4)(y2-4)
=(3y+4)(y+2)(y-2)

Use three or more sentences to describe the process you would follow to completely factor the polynomial 3x6+24.

Honors Only: Look at the equation y10n - 2y5n+1 and determine if it fits the conditions of one of the special cases listed above. Explain why the trinomial is or is not a special case and describe your process for factoring it completely. Be sure to use three or more sentences in your explanation. If the polynomial can be factored, then factor

2007-08-07 13:38:29 · 3 answers · asked by indy_pwns 1

Find the lateral area of a hexagonal prism with base edges all equaling 8 cm and height of 14 cm.

2007-08-07 13:35:30 · 2 answers · asked by zerokun4 1

Yeah Well i dont get how to do this one particular one
x - 4y + 3z = -27
2x + 2y - 3z = 22
4z = -16

2007-08-07 13:30:30 · 9 answers · asked by iCE m 2

Substitute the two whole number values immediately to the left and right of h into the function to find the corresponding y. Fill in the following table. Make sure your x-values are in increasing order in your table.

x y



h =__


thank you

2007-08-07 13:27:03 · 1 answers · asked by quepid622 1

with the following function: f(x) = x^2 + 4x + 1 find h, the x-coordinate of the vertex of this parabola.

thank you

2007-08-07 13:22:31 · 1 answers · asked by quepid622 1

2007-08-07 13:11:55 · 6 answers · asked by Anonymous

2007-08-07 13:10:01 · 2 answers · asked by Anonymous

On my homework it asks things like "describe the locus of all points in space that are 2cm above a plain" or "describe the locus of all points that are 5cm from line p".

Please give me your best child-definition (simple) on what a Locus is. Thank you.

2007-08-07 12:29:41 · 1 answers · asked by Someone 1

How do I check to see if the first equation equals the second equation?


I distribute the 11x^2 to the 9x and -x^2 ?

And distribute the 7 to the 9x and -x^2 ?

Maybe someone can help me

Thanks

2007-08-07 11:59:24 · 4 answers · asked by Anonymous

2007-08-07 11:53:40 · 4 answers · asked by diana 1

help with these problems please teach me how to do

1) List all real values ofx such that f(x)=o. If there are no such real x, type DNE in the answer blank. If there is more that one real x, give a comma separated list (i.e.: 1,2).

f(x)=12+17/x-4

2)Evaluate the function f(x)=8x^2-8x+10 at the indicated values

f(x^2)=?

3) find the Domain of -3x^2-15x+12

2007-08-07 11:41:15 · 6 answers · asked by Anonymous

Hi, i am sorry i am working on a summer packet and i totally forgot how to do some of these things

anyhelp would be really appreciated
I dont need the answer, just a quick explanation on how to do it

the question is: Write an equation for the line that is perpendicular to 9x+3y=6 and that passes through the point (-1,5)
I tried to put 9x+3y=6 into mx+b form but coudlnt do that either
i really need to go back to school
THANKS FOR YOUR HELP

2007-08-07 11:33:22 · 4 answers · asked by pandagrl1992 2

HELP!!!

2007-08-07 11:31:58 · 3 answers · asked by Anonymous