Tuesday

September 27, 2016
Total # Posts: 1,622

**Math**

commutative

*October 19, 2009*

**algebra**

You can also do them with the formula (y-y1)/(y2-y1) = (x-x1)/(x2-x1) So: (y+1)/(5/2+1) = (x+1/2)/(3+1/2) y+1 = x+1/2 y = x - 1/2 and (y+3) /(9+3) = (x-6)/(-1-6) (y+3) / 12 = (x-6) / -7 -7y -21 = 12 x -72 y = -12x/7 +51/7

*October 19, 2009*

**math**

Ms. Sue has the right idea! I was trying to explain this in a big long answer, but wasn't getting anywhere useful. Actually, I think this question is phrased confusingly. I think it should say "use x to represent _the number of houses with_ floor plan #1 and y to ...

*October 19, 2009*

**statistic**

Find a Percentile to Z-Score Calculator. You can Google one, and likely there's a table of this in your text. That'll tell you how many SD below the mean you have to go. I make it about -1.28 standard deviations, so that'll be about 34,000 - (1.28 * 2000)

*October 19, 2009*

**Gr. 12 Data Management**

Wikipedia. List_of_poker_hands

*October 18, 2009*

**Gr. 12 Data Management**

OK. I owe you an answer for that mistake, so try 13C4 * (4C1)^3 * 4C2 * 4 which also accords with Wikipedia's answer.

*October 18, 2009*

**Gr. 12 Data Management**

This one's a lot easier. :-)

*October 18, 2009*

**Gr. 12 Data Management**

Sorry, so it is.

*October 18, 2009*

**Gr. 12 Data Management**

Answered below.

*October 18, 2009*

**Math **

Ah. I see. I was reading it differently. (x^2-5x-24) (x-3) --------- * ------ (x^2-6x+9) (x-8) = ((x-8)(x+3)(x-3))/((x-3)(x-3)(x-8)) x-8 and x-3 cancel top and bottom, and leave you with: (x+3)/(x-3)

*October 18, 2009*

**Math **

x^2-5x-24 = (x-8)(x+3) x^2-6x+9 = (x-3)(x-3) Make sure you understand these two first! Factoting x^2 + ax + b, you look for two numbers that ADD to a, but MULTIPLY to b. So in the first case, 6*4 = 24, but they don't add to 5, no matter where I put the minus. But -8 * 3 ...

*October 18, 2009*

**Math **

You're welcome.

*October 18, 2009*

**Math **

Yes! When you get confused because there are just too many letters and numbers, try to isolate them and look at one at a time. The secret of success is getting used to being confused. :-)

*October 18, 2009*

**Math **

Your answer is absolutely right, but just not yet simplified. You should see that you can divide by 3 top and bottom. That reduces the constants to 121 and 33. Now look at the x and q terms without the constants: x^3q^6 ------ xq^3 Can you divide top and bottom by x? By q? By ...

*October 18, 2009*

**Math **

1. is correct, but not completed: (21+22)/98w (careful to use the brackets) =43/98w 2. I went wrong on this one myself, by taking the question down wrong, but I have it straight now. Divide 6b/(9b-27) top and bottom by 3. You can do that without changing its value. So 6b/(9b-...

*October 18, 2009*

**math**

Maybe.

*October 18, 2009*

**Math**

Um, no. Wrong turn somewhere. It's a LOT simpler than that. Your numerator will be : (1-sinx)(1+sinx) - cos^2x

*October 18, 2009*

**Math**

Do you mean solve it or prove it? It is an identity, so there really isn't a specific solution: it's true for all x. I suggest you try reformatting as (1-sin x)/cos x - cos x/(1+sin x) = 0 Then bring both fractions to the common denominator (cosx)(1+sinx), and I think ...

*October 18, 2009*

**fin 200**

When the yield curve is upward sloping, generally a financial manager should: A. utilize long-term financing B. lease C. utilize short-term financing D. wait for future financing

*October 18, 2009*

**writing**

Googling, I am guessing that this is from "The Adventures Of Ulysses" by Evslin, and that that book mostly extracts stories from The Odyssey. I don't know Evslin, but given the Odyssey as a source, I can guess at the characterisation. He sailed in a ship to ...

*October 18, 2009*

**Financing**

Look up the definitions of "quick ratio" and "current ratio". What is the difference? The major difference in most companies will be the size of inventory as a current asset. The quick ratio will always be smaller than the current ratio. From that, you can ...

*October 18, 2009*

**Financing**

quick ratio that is much smaller than the current ratio reflects A. a small portion of current assets is in inventory. B. that the firm will have a high inventory turnover. C. that the firm will have a high return on assets. D. a large portion of current assets is in inventory.

*October 18, 2009*

**algebra**

It was just too easy for you! That happens quite a lot. To everyone, especially me. :-) I look at a problem and think "I don't get it", and 10 minutes later when I'm thinking about something else, I get the "DOH!". Me and Homer Simpson. And now you...

*October 18, 2009*

**algebra**

Oh, come ON! This one's a no-brainer. You could do it in your sleep, if you're the same rachel who posted earlier today :-) Draw the axes. Draw the point (2,4). Draw a horizontal (across) line through it. What value of y does every point on that line have? So the ...

*October 18, 2009*

**Gr. 12 Data Management**

I'm not sure how this is data management. Anyway, I found this one longer and trickier than I first thought it would be. Calculating the number of hands without pairs is easy: You can choose from 52 for your first card. That rules out that card and the three others of same...

*October 18, 2009*

**finance**

LIFO = Last In First Out. Whatever you just bought, or made, is what you sell next. If I start with 5 units @$10, then buy 7 @$20, then sell 10, which 10 do I sell? I sell the _last_ 10 that I got, which will be the 7@$20 and 3 of the 5 @$10. That will leave me with the first ...

*October 18, 2009*

**algebra**

You have a start point 4 miles from the origin, when this story begins. You then walk at a rate of speed for a specified time. There really isn't much equationing (which isn't a word!) to be done here, since you know your speed and time: Distance from start point = 4 ...

*October 18, 2009*

**algebra**

You're welcome, Rachel.

*October 18, 2009*

**algebra**

All correct!

*October 18, 2009*

**Math Help Please**

answered below, at length

*October 17, 2009*

**9th grade**

There isn't a question here.

*October 17, 2009*

**Math**

answered below

*October 17, 2009*

**Math-Triangles**

Sara, I understand what you're doing, but I think the question wasn't put clearly. Neither of the triangles here is right-angled. The two triangles are similar: their sides have the same ratio. We know one is 2*7:3*7:4*7 and the other is 2*9:3*9:x and we need to find x.

*October 17, 2009*

**Math-Triangles**

I answered this below, but you didn't specify that the triangles are similar in the original question. That means that the clue is in my original answer.

*October 17, 2009*

**MATH**

Noting that ACK is not the same as KAC, You can choose from 5 letters for your first Then you can choose from 4 letters for your second. Finally you can choose from 3 letters for your first So you can choose in 5 * 4 * 3 ways.

*October 17, 2009*

**9th grade (math)**

answered below, for "kevin"

*October 17, 2009*

**physic**

OK, now I see the whole question. No, your number is right but you need to check your direction. Take two steps east, 2 steps north, 2 steps south. You are now two steps ____ of where you started.

*October 17, 2009*

**physic**

If your question was: "julianna walked 45 meters WEST, 45 meters south , and 45 meters north" then you are correct!

*October 17, 2009*

**Math**

Yes, absolutely! Try this: 18 : 27 : x = 2*9 : 3*9 : x 14 : 21 : 28 = 2*7 : 3*7 : 4*7 Clearer now?

*October 17, 2009*

**Math**

I don't understand the question. You have only one missing length for two triangles? I do note that the ratio of sides in the two cases is 2:3:(1/3)x 2:3:4 Just considering triangle 1, x could be anything less than 45 (bonus question: why?). Maybe you want x so that the ...

*October 17, 2009*

**Math**

Only back for a few minutes. Then I have to go help a grown-up whose "homework" is even harder than yours. :-)

*October 17, 2009*

**Math**

Suppose the price today is 100. In one year, that'll be 106, which is 100 * 1.06. The next year, it'll be 6% up again, which is 106 * 1.06 = 112.36 The next year after that, it'll be 6% up again, which is (106 * 1.06) * 1.06 = 112.36 * 1.06 = 119.10. You seeing a ...

*October 17, 2009*

**math**

The best way to do question 1 is to draw a graph of each. Draw your x, y axes, then find two points on each of the lines, then use a ruler to draw the line that they're both on. Which two points? Any two will do, but it's easier to draw if they're not too close ...

*October 17, 2009*

**operating system**

I only have time for a short answer at the moment. You need to sort by the PPID parent process ID first, so that you can trace each process back through its parents. Everything traces back to 0 eventually. Example: Process 6017's parent is 6003. 6003's parent is 1. 1&#...

*October 17, 2009*

**Math**

You're welcome!

*October 17, 2009*

**Math**

Let's estimate the problem first. Handy to check our thinking. There are 3 tiles per foot, right? And there are a bit over 10 feet to tile, at 3 tiles per foot, so our answer is going to be near 30 tiles. If you multiplied 1/3 by 10, you'd get about 3 as an answer, so ...

*October 17, 2009*

**Math**

(Yes I did, but I'm back. Hey, it's Saturday!) Yes! Not that the _current_ average is .2857, just that the average of the new games that are added on is .2857. If Harry batted exactly .308 in the next 28, his average would stay the same, at .308. If he bats lower, the ...

*October 17, 2009*

**Math**

Forget his current average for a minute. Now, what batting average does 8 hits in 28 make? (Divide 8 by 28.) We don't know how that .308 was made up, but we know that if 8/28 is greater than .308, he's batting better than his past average, so the average will go up. ...

*October 17, 2009*

**Math**

No, the sale price of the house doesn't matter. It could be 6,000 or 6,000,000; we don't care for this purpose. What we know is that for every 6 dollars Stephen borrows, he has to pay 7 back. What we don't know, that we would like to know, is how long Stephen has ...

*October 17, 2009*

**Math**

Interest is usually shown as a percentage rate per year, but since we don't know the number of years, we can't calculate it here. Mortgages are usually for 10-30 years. If it was one year, which would be very very short for a mortgage, the rate would be 1/6, since he ...

*October 17, 2009*

**Math**

I presume that by mortgage here is meant to total value to be paid back for the loan. When the bank lends you money, you have to pay back more than you borrowed, the extra being the interest. We don't know how much Stephen borrowed, but we know he has to pay back 7/6 of ...

*October 17, 2009*

**Math**

The reason you didn't think of that is just that you haven't had enough practice yet. :-) Keep plugging at it, and you'll be doing these things without even having to think about them!

*October 17, 2009*

**Math**

Good question! Really good question, since you're thinking of the more general case. You can't use the same trick there; I'm afraid you'll have to calculate. The standard way, that will always work, is to find a common denominator of the two fractions, so that ...

*October 17, 2009*

**Math**

Glad I could help. :-)

*October 17, 2009*

**Math**

Right! If it's bigger than one, the number on top is larger. Now, is 19/6 greater or less than one? Is 4/27 greater or less than one? So without calculating anything, you can show that the two fractions cannot be equal.

*October 17, 2009*

**Math**

I like this question! It's simple, but should make you think, and there are many ways to approach it. I'd hate to deprive you of the thinking experience, but here are some questions for you. What does it mean for a statement about numbers being equal to be "true&...

*October 17, 2009*

**Science**

Search for "population ecology" and "population biology". You might find what you're looking for there. I think "population ecologist" may be the term you're looking for.

*October 17, 2009*

**science**

answered below

*October 17, 2009*

**science**

1800g = 1.8kg How many 1.8 kg are in 80 kg?

*October 17, 2009*

**math (algebra)**

Take the next one then. Step by step. 9x = 5y + 3 Parallel, but going through (-2, 4). x is -2. y is 4. It must be 9x = 5y + something 9*-2 = 5*4 + something. What is the something?

*October 16, 2009*

**math (algebra)**

That's OK. First you solve it. Then you put it into the form you need. Point slope form just means moving y to the left hand side, and everything else to the right. Consider: x + 5y = 47 Subtract x from both sides: 5y = 47 -x Divide by 5 y = 47/5 - x/5

*October 16, 2009*

**math (algebra) -oops**

I typoed, and it might confuse you. Sorry. 5*8 is 40, or course, not 47. x + 5y = something 7 + 5 * 8 = something 7 + 40 = something = 47 So a line parallel to x+5y=2, containing (7,8) is x+5y=47.

*October 16, 2009*

**math (algebra)**

The key point to know is that: if the new line is parallel, then the coefficients of x and y will be the same (The coefficients are the numbers that x and y are multiplied by). So, taking the first one, any line parallel to x+5y=2 will be of the form x + 5y = some_number x + ...

*October 16, 2009*

**algrbra 2**

Divide the difference in the y coordinates by the difference in the x coordinates to get the slope.

*October 16, 2009*

**Algrbra 2**

This is quite straightforwatrd. x is 15, so 15 - 5*y = -25 so what is y?

*October 16, 2009*

**math**

I think maybe what's being asked is to get an equation with B on the left-hand side. A=(1/2)BH multiply both sides by 2 2A=BH divide both sides by H 2A/H = B so B = 2A/H

*October 16, 2009*

**calculus - identities**

sec(y)=1/cos(y) tan(y) = sin(y)/cos(y) Low consider left and right hand sides: LHS = 1/cos(y) - cos^2(y)/cos(y) RHS = sin^2(y)/cos(y) Now you've got everything over a common denominator, look at the top of each side, and you should see your way through.

*October 16, 2009*

**7th grade science**

Aristotle had the (very wrong) idea that things could move only as long as something was pushing them. This no doubt seemed reasonable in Earth conditions, before quantitative science, when just about everything that moves is pulling against gravity or friction. In a vacuum, ...

*October 16, 2009*

**intro to software development**

If it's any comfort, I don't quite know what they're asking either, "Processes or capabilities" could mean almost anything. I have a suspicion I'm telling you much more than you need to know. If I were writing one, I'd identify: data capture (...

*October 16, 2009*

**calculus**

Differentiate to find the max height. Velocity is 64 - 32t. Max is at s'(t) = 0, when velocity is zero s'(t)= 64 - 32t = 0 so it peaks at t=2. From that you can get the height. You now need to find s(t) = 0, so solve 64+64t–16t2 = 0 That will give you the time, ...

*October 16, 2009*

**calculus**

The slope of the tangent at that point will be the same as the slope of the parabola, by definition. How do you get the slope of the parabola at that point? Differentiate it. What is the differential of 4x^2–6x+6? Now plug in x=5 to your answer, and the arithmetic gives ...

*October 16, 2009*

**Math- Graphing Calculator Use**

I'm sorry, but I'm not sure anybody will be able to help with that information. Different calculators do stats, especially, in different ways. If you specified the exact model you're using, maybe somebody reading this would have the same one, and know how it works...

*October 16, 2009*

**Calculus**

Well, the derivative of sin is cos, and the derivative of cotan is cosec^2, both of which should be in your standard list of derivatibes. Knowing that, you can just write down the answer.

*October 16, 2009*

**math **

4 seconds PLUS how many seconds in a minute? multiply that by 36 PLUS how many seconds in a minute? multiply that by how many minutes in an hour and multiply again by 23 That is, 23 * 60 * 60 + 36 * 60 + 4 For a check on your answer, it'll be a five-digit number like 8???4

*October 16, 2009*

**Calculus**

I can't find an integer n for which this is true. Consider f'(x) = 1/(2sqrt(x+6)) =1/2sqrt(52) at point x=46 You can take a factor of 4 out of that, =1/4sqrt(13) but you're still left with the irrational sqrt(13). You can't get an integer out of it unless x+6 ...

*October 16, 2009*

**physics**

The flash and the sound happen at the same time, but both the light and the sound have to travel to you, at different speeds. For fun, or extra credit, you could calculate how long the light takes to travel 8000m, but it's small enough that we can ignore it, especially ...

*October 16, 2009*

**Math**

The average is the total score divided by the number of tests. All scores are integers, so the total score is an integer. The number of tests is an integer. What is the smallest total score that, when divided by an integer, would give 4.6?

*October 15, 2009*

**english**

I can think of a four letter word that begins with f. It would work even better if the first sentence were "The weather will be _____ today"

*October 15, 2009*

**math**

Given what?

*October 14, 2009*

**pre-calculus**

That's solvable easily with calculus, not sure whether you're supposed to be using it given your heading: C'(x) = 4.9(2)x - 617 = 9.8x -617.4 at its minimum, 9.8x = 617.4

*October 14, 2009*

**geometry**

Both have four sides. Both have pairs of adjacent sides equal. A kite's opposite sides don't have to be equal, but a rhombus must have all sides equal.

*October 14, 2009*

**geometry**

a) So you're looking at a Right Angled Triangle (RAT) with the two short sides being 4 and 25. What does Pythagoras say about the other side, which must be the hypotenuse? b) This is the same question, except with 6 on the shortest side instead of 4.

*October 14, 2009*

**Programming**

Glad I could help, especially in a case like yours where you clearly could do the job yourself, but just hit a snag. Good luck with it!

*October 14, 2009*

**Programming**

Given the short deadline, and that I'll be away for a while, I hacked nastily into your code, to produce something that runs all the way through, I think. I want to emphasise just how ugly this is, and that it needs a lot of work to be a worthy project! But it runs, and if...

*October 14, 2009*

**Programming**

I'll be away until tonight. How long do you have for this project?

*October 14, 2009*

**Programming**

OK, doing what I said last is really easy. Just move the two displays abve the loop, and actually draw the board instead of just returning it, like: myGame.getPrompt(); myGame.getRules(); while(myGame.winner() == 0 && !myGame.placeMarker()) { System.out.println(myGame....

*October 14, 2009*

**Programming**

I think you want a String rather than a char. Here's what I did: 1. I made a little batch file to recompile and rerun, containing javac TicTacToe.java jar cvf TicTacToe.jar TicTacToe.class javac -cp .\TicTacToe.jar Lab2.java java -classpath . Lab2 I don't know whether ...

*October 14, 2009*

**Programming**

Just home and had a quick look. My two immediate thoughts: 1. You need to write getCurrentPlayer() in TicTacToe so that you can get the whole thing to start running, from where you can get a handle on what it is doing. 2. I still don't think the instructions I/O should be ...

*October 14, 2009*

**Programming**

Nice to see you back, Tim. I'll be away from the forum until tonight, but somebody else may help in the meantime. To help them help you, you could post your thinking, given your current code. Where are you stuck? What doesn't seem to be working that you think should be...

*October 14, 2009*

**Chemistry**

After 0.6523 g of is heated, the residue has a mass of 0.3423 g. Calculate the % H2O in the hydrate.

*October 13, 2009*

**math**

two equations : n+d=42 .05n+.10d=3.85 or 5n+10d=385

*October 13, 2009*

**3rd grade**

if you round the number to the tens place, it is 460 if you round the number to the hundreds, it is 500 could the number be 468 and why

*October 13, 2009*

**Math**

a. (13-2)/32 = b. @1000 it had 11/32. @20000 it had 5/32. So after 19,000 it lost 6/32. It needs to lose another 3/32 to be "worn out". You should be able to see the number of miles from that.

*October 13, 2009*

**math**

Oh. If it's any comfort, I have no idea how writing sentences embodying equations could be proven, either.

*October 13, 2009*

**math**

The question wants you to figure out what number replaces X. 7 = x + 5 7 = ? + 5. What number replaces x, or the question-mark? You're going to write: x = (some digit, which is your answer) Proving is easy. Just write 7 = x + 5 down again, but this time replacing x with ...

*October 13, 2009*

**math**

"maximum: 8, range: 6" gives you your minimum number, so pencil that in, and 8 at the other end of course to make your maximum. Now, if you know what mode and median mean, you should be ready to write in some 6s, and spread about the same number of lower digits.

*October 13, 2009*

**math**

Well, we're going to need three lots of some unknown number plus 4. Let the three be bags. Since we're near Halloween, let's say some unknown number of pieces of candy get divided equally into 3 bags. Then let's say somebody adds 4 pieces to each bag. Can you ...

*October 13, 2009*

**Math- fractions and decimals**

"62 and a half" is 62.5, or 62 1/2, or 125/2. That's all fine. But you talked about a hundred chart. I wonder whether you mean what 62.5 is as a fraction of a hundred, which is the same as asking what 62.5% is as a fraction. Does your 100 chat show 50 as being 1/...

*October 13, 2009*

**Algebra**

I'm totally with you on y=8, but the best way to check your answer is to substitute the value back in. Now try y=2/3: Is |2/3+3| + 5 = 2(2/3) ? Is 11/3 + 15/3 = 4/3 ? I think you took a wrong turn at: "Now, the two equations are 3=y-5 and 3y+3=5." You can't ...

*October 13, 2009*

**Algebra**

The perimeter is two lengths + two widths, and that has to be more than 70. 2L + 2W > 70 We know that the length is 19, so 2L = 38. 2W + 38 > 70 2W > 70 - 38 Now pick a width that makes that true. There are lots of them to choose from: a million will do. :-)

*October 13, 2009*