Science & Mathematics - 19 September 2007

solve for x and y using elimination or substitution methods of solving systems.

this is the problem

3x+y=6
-3+4y=9

please helop me.

2007-09-19 12:00:53 · 5 answers · asked by lalala 2 in Mathematics

Can you still use the fittings,after they are cleaned, in a potable water system. In other words we have a lot of copper and brass fittings that need to be cleaned so we can use them in the plumbing systems of new houses and not be a health risk because of what they have been cleaned with.

2007-09-19 12:00:19 · 4 answers · asked by Anonymous in Engineering

ok, so im doing linear equations in math and we had a sub. today who didn't bother to explain anything and was pretty pissy so i decided not to ask questions. anyone know how to do these? ex. 3x=5y and 3/x + 4/y =2 has something to do with moving around the numbers/letters. please.

2007-09-19 12:00:07 · 2 answers · asked by Anonymous in Mathematics

500= 1.259921^T

Please tell me how to separate out the T in steps.
I just can't remember the process

2007-09-19 11:58:17 · 5 answers · asked by ~Bagon~ 2 in Mathematics

2007-09-19 11:54:52 · 1 answers · asked by here4&2help 1 in Mathematics

The ultimate question I'm sure we're all wondering: Are we alone?

2007-09-19 11:52:35 · 16 answers · asked by Anonymous in Astronomy & Space

2007-09-19 11:51:40 · 1 answers · asked by D 2 in Mathematics

the alternative form of the derivative ---
the limit as x approaches c of ( f (x) - f (c) ) / x - c.

the problem is f (x) = 4 - (x-3)^2 and c=2.

Showing work is very much appreciated.

2007-09-19 11:49:45 · 2 answers · asked by Merihime 1 in Mathematics

i need atleast 10 and i need help on i because i have lie 7 more homeworks to do.....plz...help...dont leave anything that isnt significant to my question thank you!!!

2007-09-19 11:49:00 · 9 answers · asked by medicated kiss 2 in Astronomy & Space

solve algebraically

2007-09-19 11:47:44 · 3 answers · asked by tttt 1 in Mathematics

Explain and show calculations.
1. Whats the frequency in vibrations per second of a 100 hertz wave?

2. The Sears building sways back and forth at a vibration frequency of about 0.1 Hz. Whats the period of its vibration?

3. A water wave vibrates up and down 2 times each second and the distance between wave crests is 1.5 meters.

a) whats the frequency of the wave?

b) whats the wavelength of the wave?

c) whats the speed of the wave?

4. Whats the wavelength of a 340 Hz sound wave when the speed of sound in air is 340 meters per second?

( period = seconds/cycle , frequency = cycle/second)

2007-09-19 11:47:30 · 1 answers · asked by ... 2 in Physics

A) Watch tv talk shows
B) the general requirements of a technical position
C) Attend trade shows
D) Visit museums

2007-09-19 11:47:29 · 4 answers · asked by Schnickyyy 1 in Engineering

2007-09-19 11:46:49 · 9 answers · asked by C&M 3 in Mathematics

ok well im in the 9th grade, and need a science fair topic. i want to do one with my hamster or chinchillas (i've done ones with my chinchillas last 2 years and keep gettin runnerups) im in honors class so i cant do anything like type of food affecting this or type of cage affecting that. i need something hard. well medium to hard


pleasseeee help me

2007-09-19 11:45:20 · 1 answers · asked by dimndbabe 1 in Other - Science

thrown at an angle of 29.0° with the horizontal. At what speed must the second ball be thrown so that it reaches the same height as the one thrown vertically?

2007-09-19 11:40:59 · 1 answers · asked by hockeywinger14 1 in Physics

Knowledge industry that...

A) Manages and conveys Information.
B) Creates and conveys information.
C) Has knowledge as its product.
D) Has information as its goal.

can anyone help me out without telling me to do my own work?
thanks :]

2007-09-19 11:40:36 · 3 answers · asked by Schnickyyy 1 in Engineering

A red-eyed female fruit fly is crossed with a red-eyed male fruit fly. All of the female offspring have red eyes but only one-half of the male offspring are red-eyed. The other half of the male offspring have white eyes. In this example, eye color in fruit flies:

A. is an X-linked trait
B. exhibits lack of dominance
C. is influenced by the environment
D. is controlled by several genes

I know I can cross out C. I kind of want to say A, but I'm not too sure. Can anyone help me out? Am I right or am I wrong?

2007-09-19 11:39:00 · 4 answers · asked by proudmommy306 2 in Biology

I have a biology rain forest thing and i'm not sure if i am classifying the animals right. Are STICK SPIDERS omnivores or herbivores or what?? plz i need help!!

2007-09-19 11:38:20 · 1 answers · asked by luvstruck4987 2 in Biology

While riding on an elevator descending with a constant speed of 2.4 m/s, you accidentally drop a book from under your arm.
(a) How long does it take for the book to reach the elevator floor, 1.2 m below your arm?
s
(b) What is the book's speed relative to you when it hits the elevator floor?
m/s

2007-09-19 11:38:20 · 1 answers · asked by jkopinto 1 in Physics

1) think of fellow workers
2) consider where you want to end up
3) evaluate the rewards
4) make a list


could anyone possibly help me out with insulting me or telling me that i should do my home work FYI its called yahoo ANSWERS

2007-09-19 11:37:22 · 3 answers · asked by Schnickyyy 1 in Engineering

Standing at the edge of a cliff 36.0 m high, you drop a ball. Later, you throw a second ball downward with an initial speed of 8.0 m/s.
(a) The speeds of both balls increase when they reach the base of the cliff. Is the increase of the first ball's speed greater than, less than, or the same as that of the second ball?
greater than
less than
the same as



(b) Verify your answer to part (a) with a calculation. (v) of each.
v = ? m/s (first ball)
v = ? m/s (second ball)

2007-09-19 11:37:00 · 1 answers · asked by jkopinto 1 in Physics

So, I just started my junior year of college and apparently can' do 3rd grade math.

Here's part of my brother's math homework. Could someone explain it to me so I can help him out?

Ben says that he multiplied twice to find the number of cups in three quarts. Describe the steps Ben took to find the answer.

Help please?

2007-09-19 11:36:56 · 11 answers · asked by Anonymous in Mathematics

ground at an angle of 49 degrees With what speed, in SI units, must the animal leave the ground to reach that height?
m/s

2007-09-19 11:36:25 · 1 answers · asked by hockeywinger14 1 in Physics

i need help with this problem:

find the measure of angle T if the measure of angle T is 20 more than four times its supplement.

i'm not sure how i can set it up...


-thanks :)

2007-09-19 11:34:48 · 3 answers · asked by gratisfaction. 5 in Mathematics

they wont believe you when you say wet paint

2007-09-19 11:34:38 · 11 answers · asked by Anonymous in Astronomy & Space

2007-09-19 11:31:46 · 2 answers · asked by quickfast 1 in Engineering

I want to learn about them, it seems hard!

2007-09-19 11:31:39 · 9 answers · asked by Anonymous in Astronomy & Space

can you help me find the equation of a line that goes through (3,7) with undefined slope?

2007-09-19 11:31:38 · 1 answers · asked by Juan C 6 in Mathematics

I want to be an electronic engineer, but I dont know how much I'll get pay. So I want to ask y'all about it.

2007-09-19 11:31:36 · 0 answers · asked by 1122334455 2 in Engineering

I wanted to test to see if caffeine effects the heart beat rate in mice. Mice have a higher heart beat rate than humans. I predict the caffeine will affect the heartbeat of mice. I went and bought fourty of the same species of mice, all around the same age. I put 20 mice in one 4x5 cage, and the other 20 in another 4x5 cage. In one of the cages I fed each of the mice a treat covered in caffeine. I waited 15 minutes (the average time it takes for caffeine to kick in) and hooked up each of the mice to a machine. The machine tracks heartbeats per minute. I fed the other cage the same type of treats, but with no caffeine on them. The average heart beats per minute in the caffeine dosed group was 78 per minute. The non-caffeine dosed group had an average of 62 per minute. My hypothesis was correct, caffeine does affect the he

2007-09-19 11:31:24 · 4 answers · asked by Anonymous in Biology