Sunday

August 30, 2015
Total # Posts: 3,043

**chem**

A 2.241 g sample of nickel reacts with oxygen to form 2.852 g of the metal oxide. Calculate the empirical formula of the oxide. 1)NiO Give the number of moles of each element to support you answer. moles of Ni 2) 1.339 mol moles of O 3)1.34 mol I know #1 is correct but 2 and 3...
*November 12, 2010*

**science**

suppose you had two samples of the same radioactive isotope. one sample had a mass of 25 grams. the other had a mass of 50 grams. would the same number of particles be ejected from each sample in the first hour? explain
*November 11, 2010*

**chem**

oh i see! thanks
*November 11, 2010*

**chem**

shouldn't it be less than the 4.7 g of silver plating??
*November 11, 2010*

**chem**

so the mass would be 6.24g?
*November 11, 2010*

**chem**

Silver chloride, often used in silver plating, contains 75.27% Ag. Calculate the mass of silver chloride in grams required to make 4.7 g of silver plating.
*November 11, 2010*

**chem**

i got the answer. thanks anyways!
*November 11, 2010*

**chem**

A 4.91 g sample of aluminum completely reacts with oxygen to form 6.85 g of aluminum oxide. Use this data to calculate the mass percent composition of aluminum in aluminum oxide. i got 61.2% first and it was wrong. then i got 53.0% and it was wrong
*November 11, 2010*

**Math**

I figured it out. -8=1/3x+x -8*3=1/3x*3+x -24=3x+x -24=4x -24/4+4x/4 -6=x -8=1/3*-6+-6 -8=-6/3-6 -8=-2-6 -8=-8
*November 10, 2010*

**Math**

-8=1/3x+x
*November 10, 2010*

**chem**

I used that answer and it was wrong. we have a practice version : the question was A salt crystal has a mass of 0.18 mg. How many NaCl formula units does it contain? and the answer was 1.9e+18 formula units. so wouldn't the answer for my question be in the positive exponents?
*November 10, 2010*

**chem**

so i posted this question yesturday and got some help. which is the stuff below. can you look at the last thing i said which was the answer i got by doing what DrBob222 said to do and tell me if its correct.(the question is the first section) thanks chem - hannah, A salt ...
*November 10, 2010*

**social studies**

1. Cuzco 2. are there many? this is what i found. In 1528, Emperor Huayna Capac (Young Lord) ruled the Inca Empire 3.Mound Builders
*November 10, 2010*

**math**

substract 3 from the right side and left eg- -1=3+4x -3 -3 then divide by 4 on the right and left side. eg- -4/4=4x/4 x=-1
*November 10, 2010*

**math**

first we want to get the like terms on the same side. so lets subtract 3 from both sides you get -4=4x then since we want x by itself we divide by 4 on both sides making the 4 cross out and we get -1=x
*November 10, 2010*

**Spanish 1**

the first 3 are def. correct. for the last one it seems like many could work. im not sure about that one either sorry but if i had to guess id think either a or b
*November 10, 2010*

**Spanish 1**

a)a-there b)d- a pencil
*November 9, 2010*

**math**

estimating quotients 811 divided by 2
*November 9, 2010*

**chem**

thanks so much!
*November 9, 2010*

**chem**

How many moles of O are in 13.5 mol Fe(NO3)3? i got 7.32e25 but soon realized that is totally wrong.
*November 9, 2010*

**chem**

so it would be .000006845 formula units?
*November 9, 2010*

**chem**

so do i have to convert .4 mg to grams first? that would be .0004 right? so then i just divide .004/58.44 and that will be my answer?
*November 9, 2010*

**chem**

nevermind i got the answer but i do have another question: A salt crystal has a mass of 0.40 mg. How many NaCl formula units does it contain?
*November 9, 2010*

**chem**

Determine the mass(in grams) of each of the following compounds. a) 0.709 mol magnesium fluoride i got 30.7grams but it was wrong. id appreciate the help! thanks! also if i end up getting the help i have a couple other questions
*November 9, 2010*

**Math(Please help)**

Show that (f X g)(x) = (g X f)(x) = x for f(x)= 3x-5 and g(x)= x+5 / 3 I have know idea how to do this.
*November 8, 2010*

**Math**

Find the inverse of the function f(x) = x / 2x+1 I know that you would make this x= y / 2x+1 but now I do not know what to do.
*November 8, 2010*

**Math**

Find the domain of (f X g)(x) if f(x) = 2 / x-3 and g(x) = 1 / x+4. I know the domain for g(x) is x cannot be -4 but I do not know what else to do.
*November 7, 2010*

**Math**

Find the inverse of the function f(x) = x / 2x+1 I know that you would make this x= y / 2x+1 but now I do not know what to do.
*November 7, 2010*

**chemistry**

The molality of a solute is the number of moles of that solute divided by the weight of the solvent in kilograms
*November 4, 2010*

**Math**

The following function f is one-to-one; find its domain and range. f(x) = 5 / x+3 Domain = x cannot be -3 Range= I do not know how to find this.
*November 4, 2010*

**Math(Please check)**

Sorry I already post this. Disregard this one.
*November 4, 2010*

**Math(Please check)**

Find the domain of the following rational function. R(x) = -3x^2 / x^2 + 2x - 48 (x+8)(x-6) So domain is x cannot be 8 or -6. Am I correct?
*November 4, 2010*

**Math(Please check)**

Find the domain of the following rational function. R(x) = -3x^2 / x^2 + 2x - 48 (x+8)(x-6) So the domain is x cannot be 8 or -6. Am I correct?
*November 4, 2010*

**math**

Thank You!
*November 4, 2010*

**math**

The function D(h)=7e^-0.4(h) can be used to determine the milligrams D of a certain drug in a patient's bloodstream h hours after the drug has been given. How many milligrams will be present after 9 hours. Round three decimal places. so 7e^(-0.4 x 9) = .191 To get this ...
*November 4, 2010*

**English**

Thank you!
*November 3, 2010*

**English**

Most people think of bamboo as a tree or a bush. Is this transitive or intransitive? think = transitive
*November 3, 2010*

**Math**

The function D(h)=7e^-0.4(h) can be used to determine the milligrams D of a certain drug in a patient's bloodstream h hours after the drug has been given. How many milligrams will be present after 9 hours. Round three decimal places. so 7e^(-0.4 x 9) = .191 To get this ...
*November 3, 2010*

**Math**

Find the x and y intercepts of the following function. f(x) = 9x - x^3
*November 3, 2010*

**Math(Quick question)**

The function D(h)=7e^-0.4(h) can be used to determine the milligrams D of a certain drug in a patient's bloodstream h hours after the drug has been given. How many milligrams will be present after 9 hours. Round three decimal places. so 7e^(-0.4 x 9) = .191 To get this ...
*November 3, 2010*

**Math(Please check)**

O ok I understand. Thanks!!
*November 3, 2010*

**Math(Please check)**

So what is the inverse?
*November 3, 2010*

**Math(Please check)**

The following function is one-to-one; find its inverse f(x)=x^3+5 I know that the first step would be to set y = to x so I did y=x^3+5 Then you swap x with y so x=y^3+5. Then you solve for y and this is where I think i messed up. I did y^3=x-5 = y=x^3-5 Then the inverse would ...
*November 3, 2010*

**Maths**

What is dy/dx of e^-x ?
*November 2, 2010*

**elementary functions**

(x-4)(x+1)
*November 2, 2010*

**algebra**

1. (4x-3)(x-1) 2. Use the quadratic formula which you can find on youtube.
*November 2, 2010*

**Maths**

if f(x) = 2x - x ln x show that f(e^3) = -e^3 I know you have to substitute e^3 into the function, so Ive sone ths so far: 2e^3 - e^3 ln e^3 What is the next step?
*November 1, 2010*

**MATH**

you do do 24 divided by 8 and then times it by 7.
*November 1, 2010*

**Maths**

if f(x) = 2x - x ln x show that f(e^3) = -e^3 I know you have to substitute e^3 into the function, so Ive sone ths so far: 2e^3 - e^3 ln e^3 What is the next step?
*November 1, 2010*

**Calculus **

Determine whether the integral is divergent or convergent. If it is convergent, evaluate it and enter that value as your answer. If it diverges to infinity, state your answer as "INF" (without the quotation marks). If it diverges to negative infinity, state your ...
*October 22, 2010*

**Calculus **

Find the area between the curves y=(x^3)-10(x^2)+24x and y=(-x^3)+10(x^2)-24x
*October 22, 2010*

**Calculus **

Apparently it diverges to negative infinity. Can someone please explain to me why?
*October 22, 2010*

**Calculus **

Determine whether the integral is divergent or convergent. If it is convergent, evaluate it and enter that value as your answer. If it diverges to infinity, state your answer as "INF" (without the quotation marks). If it diverges to negative infinity, state your ...
*October 22, 2010*

**History**

34. Designed as an attempt to secure the loyalty of the French to their new rulers, this act broke new ground in toleration and statesmanship. Unfortunately for the British, the Americans saw only sinister designs. This act was the a. Treaty of Paris, 1783 b. Tea Act c. Statue...
*October 22, 2010*

**social studies**

What is an example of Human-Environment Interaction in Vatican City?
*October 20, 2010*

**Physics**

Oh gotcha. But how come friction=centripetal force? I thought since net force is towards the center they can't cancel each other out like that...
*October 19, 2010*

**Physics**

How come a heavy truck and a small car can both travel safely at the same speed around an icy, banked-curve road? I would think that since mass is increased, normal force is therefore increased, and force of friction is therefore increased. And since the opposing force, the ...
*October 19, 2010*

**physics**

(a) 264 (b) 461.49 (c) 0
*October 18, 2010*

**Algebra**

A saline solution was made by mixing 11 ml of a 36% saline solution and 6 ml of a 53 % saline solution. How do I find the consentration of the new mixture?
*October 18, 2010*

**6th grade math**

what is the answer showing work to 8(2h-10)=16h
*October 17, 2010*

**Chemistry**

nevermind i got it. thanks
*October 14, 2010*

**Chemistry**

What are the charges of the ions in an ionic compound containing iron(III) and fluoride ions? a)iron(III)- i got 3+ b) flouride- im not sure on this one c)Write the formula for the compound. (Type your answer using the format CO2 for CO2.) - Fe3F2... i rly have no idea on this...
*October 14, 2010*

**repost-chem**

ok. thanks. I have a question about it that i posted on my previous post. think u could check it out? thanks
*October 13, 2010*

**repost-chem**

Write a formula for the compound that forms from barium and the following polyatomic ion. (a) hydroxide (b) carbonate (c) phosphate (d) hydrogen phosphate basicaly all i know is that all of these are going to start with Na. I need major help! thanks:)
*October 13, 2010*

**chemistry**

I get the first 2 but how did u get the second two?
*October 13, 2010*

**chemistry**

Write a formula for the compound that forms from barium and the following polyatomic ion. (a) hydroxide (b) carbonate (c) phosphate (d) hydrogen phosphate basicaly all i know is that all of these are going to start with Na. I need major help! thanks:)
*October 13, 2010*

**Math**

Find the equation for the line with the following. parallel to the line 8x+7y=-7 and containing the point (7,-7) Since it it parallel the equation would have to have 8x, right? Then im not sure what to do.
*October 7, 2010*

**Math**

Find all points having x-coordinate 9 and distance 10 from the point (3,-2). Would I use the distance formula here?
*October 7, 2010*

**Math**

So for the diameter I got 136. This that right?
*October 7, 2010*

**Math**

Find the center and the radius of the circle which (6,-2) and (-4,4)are endpoints of a diameter. Please help!
*October 7, 2010*

**Math**

Find the requested function and state its domain: f(x)= 4x+3 g(x)=4x-5 Find f/g and its domain. So I did 4x+3/4x-5, so the 4x's cancel out and 3/-5 is left. So my answer is 3/-5. Is this correct Now I just need to find the domain which I am not to sure about.
*October 7, 2010*

**math**

how can you use rounding to estimate 331+193
*October 7, 2010*

**Math**

I got y=-10/3 x + b Then I used (-5,4) so 4=-10/3(-5) + b and I got y=-10/3x - 46/3. I am not sure if I multiplied and added the fractions correctly
*October 7, 2010*

**Math**

Find an equation for the line with the given properties. Containing the points (-5,4) and (-2,-6) Please help!
*October 7, 2010*

**Math**

Given the function f(x)= x^2-3 / x+1, what point on the graph corresponds to x=-2? I have no idea what to do. Am I suppose to plug in -2 into the equation?
*October 7, 2010*

**Math**

Find the requested function and state its domain: f(x)= 4x+3 g(x)=4x-5 Find f/g and its domain. So I did 4x+3/4x-5, so the 4x's cancel out and 3/-5 is left. So my answer is 3/-5. Is this correct Now I just need to find the domain which I am not to sure about.
*October 7, 2010*

**Math(Please check)**

Determine whether the graph of the following equation is symmetric with respect to the x-axis, the y-axis, and the origin. y^2 - x - 49 = 0 For x axis -y^2 - x - 9 = 0 is not the same as the first equation so it is not symmetrical to the x-axis. Correct? For the y-axis y^2 + x...
*October 7, 2010*

**Math(Please, Please, help)**

Nevermind,I did not realize that my question was already answered.
*October 7, 2010*

**Math(Please, Please, help)**

For f(x) = 2x-3 and g(x)= 2x^2 find, a) (f + g)(x) = My answer is 2x^2 + 2x - 3. Is this correct? b) (f - g)(x) How would you do this? c) (f X g)(2) I do not know what to do since the 2 is there. Determine whether the graph of the following equation is symmetric with respect ...
*October 7, 2010*

**Math**

For f(x) = 2x-3 and g(x)= 2x^2 find, a) (f + g)(x) = My answer is 2x^2 + 2x - 3. Is this correct? b) (f - g)(x) How would you do this? c) (f X g)(2) I do not know what to do since the 2 is there. Determine whether the graph of the following equation is symmetric with respect ...
*October 6, 2010*

**Math(Please check)**

why 9?
*October 6, 2010*

**Math(Please check)**

Find the center (h,k) and radius of the following circle. x^2 + y^2 - 6x - 2y + 1 = 0 My answer is center= (-3,-1) and radius of 1. Am I correct?
*October 6, 2010*

**Math(Please help)**

Sorry I wanted to add something else! Determine whether the graph of the following equation is symmetric with respect to the x-axis, the y-axis, and the origin. y^2 - x - 49 = 0 For x axis -y^2 - x - 9 = 0 is not the same as the first equation so it is not symmetrical to the x...
*October 6, 2010*

**Math(Please help)**

For f(x) = 2x-3 and g(x)= 2x^2 find, a) (f + g)(x) = My answer is 2x^2 + 2x - 3. Is this correct? b) (f - g)(x) How would you do this? c) (f X g)(2) I do not know what to do since the 2 is there.
*October 6, 2010*

**Math**

Find the slope intercept form of the line with the following properties. Slope=4 containing the points (-2,-5) I know that slope intercept form is y=mx+b so the m is the slope which is 4 but now I get confused since they give me x any y values (-2,-5). Is it just y which is -5...
*October 6, 2010*

**Math**

These questions that I have completed are on a test review for my exam and I would just like to know if they are correct. These are only a few of the questions, I have more that are just not complete yet. Thank You! 1) List the intercepts for the graph of the following ...
*October 6, 2010*

**Math(Please check answers)**

These questions that I have completed are on a test review for my exam and I would just like to know if they are correct. These are only a few of the questions, I have more that are just not complete yet. Thank You! 1) List the intercepts for the graph of the following ...
*October 6, 2010*

**Math**

Find the slope intercept form of the line with the following properties. Slope=4 containing the points (-2,-5) I know that slope intercept form is y=mx+b so the m is the slope which is 4 but now I get confused since they give me x any y values (-2,-5). Is it just y which is -5...
*October 6, 2010*

**Math(Please help)**

Thank You!!
*October 5, 2010*

**Math(Please help)**

Write an equation of the line satisfying the given condition. a) x intercept = 3 y intercept=-2 I am really not sure how to start here. b) vertical line containing (5,-1) Would it be y=5x-1? c) parallel to the line 3x-4y=5 and containing the points (3,-6) . I know that the ...
*October 5, 2010*

**Math**

Write an equation of the line satisfying the given condition. a) x intercept = 3 y intercept=-2 I am really not sure how to start here. b) vertical line containing (5,-1) Would it be y=5x-1? c) parallel to the line 3x-4y=5 and containing the points (3,-6) . I know that the ...
*October 5, 2010*

**algebra**

oops the right numbers are suppose to be under the x
*October 5, 2010*

**algebra**

like jannie said.. so your table would look something like _y____x_ -2 -5 -1 -4 0 -3 1 -2 2 -1 3 0 4 1 you can basically choose any number you want x to be then find y
*October 5, 2010*

**Math**

yes its correct!
*October 5, 2010*

**Math**

Yep:) that is the correct answer
*October 5, 2010*

**Math**

does 2-6=2?
*October 5, 2010*

**Math**

Hm... i posted on here.. idk y its not here but.. Ok so we know that the ones place has to be 2more than the tens place so which number has ones place-tens place=2?
*October 5, 2010*

**Math**

State whether the equation defines y as a function of x. a) y=x^2-2x Yes b) y^2 = 3x-4 No c) 5x+7y=10 Yes Are my answers correct?
*October 5, 2010*

**Math(Please check! Thank You)**

List the intercepts and test for symmetry. y^2 - x - 4 = 0 I got (-4,0) and (0,2) for the intercepts. -y^2 - x - 4 = 0 Is not symmetrical to the x axis, correct? y^2-(-x) - 4 = 0 Is not symmetrical to the y axis, correct? -y^2 + x - 4 = 0 Is not symmetrical to the origin, ...
*October 5, 2010*

**Math(Please check)**

Lsit the intercepts and test for symmetry. y^2 - x - 4 = 0 I got (-4,0) and (0,2) for the intercepts. -y^2 - x - 4 = 0 Is not symmetrical to the x axis, correct? y^2-(-x) - 4 = 0 Is not symmetrical to the y axis, correct? -y^2 + x - 4 = 0 Is not symmetrical to the origin, ...
*October 5, 2010*