All Answers

+118725

kkdd:
When you have for example -6 and your plugging it in for -x would you put in 6 because of the double negative or -6

Yes

MelodyJan 9, 2014

+118725

WATS UP:
21= -10m-3 what is m?

Thanks Steve and Hello,
It is great that you offered help but how about trying to help WATS UP to understand.

wat's up,
the aim is to get m on one side by itself.
Whatever you do to one side you must do to the other side as well.
Start by adding 3 to both sides then think about what you want to get rid of next.

MelodyJan 9, 2014

+118725

samundson:
can I create my own right triangle on this program.

No you can't but if you want to describe a triangle or upload a picture of one. (my uploads are usually .jpg)
There is an upload attachment button under the submit button.
It is fairly easy to use.
I often use the 'snipping tool' which is automatically included on windows 7 and probably windows 8.
It is a brilliant little tool that you can take screen shots with and turn them into jpgs.

I use lots of other little tools but take a look at the 'snipping tool' if you haven't already used it.

If you actually want to computer generate a triangle there are a lot of programs that will do that.
just let me know if you want more information.

MelodyJan 9, 2014

+118725

apples092113:
If f(x)=6x + 4 and g(x)= -7x - 8, find (f+g)(3)

Hi apples,

(f+g)(3) = f(3)+g(3) = ( 6*3 + 4 ) + (-7*3 - 8)

You can finish it.

MelodyJan 9, 2014

+118725

Math Genius:
The population in a region varies with the number of preditors at any time, you could predict the rodent population r(t)=2500+1500sin(Pi/4*t) where t is the number of years since 1976, verify that the year 1982 was a year of minimum

Hi Math Genius,
I have assumed that the by pi/4*t you meant pi*t / 4
I don't want to actually do it for you but I am happy to help you along the way.
It is a differentiation question.
Stationary points are when the gradient of the tangent to the curve = 0 (that is dr/dt = 0)
The stationary point will be a minimum if the curve is concave up at that point. (that is d ²r/dt ² > 0)

t = 0 in 1976, so what t do you care about?

Is that enough to get you started? If you want more help show me what you have done to help yourself first.

MelodyJan 9, 2014

+5478

-9- -13/3
subtracting a negative number is the same as adding a positive number, since the negatives cancel out.
So -9- -13/3 would be:
-9 + 13/3
this is the same as subtracting 9 from 13/3
=13/3 - (9*3)/3
=13/3 - 27/3

=14/3

kitty<3Jan 9, 2014

+5478

The answers might all be e. Just might, señor;)

kitty<3Jan 9, 2014

+5478

I'm pretty sure you need more info to solve this problem:)

kitty<3Jan 9, 2014

+5478

Scientific notation has one digit before the decimal point and multiplies the number by exponents of 10.
So 508 would be written as 5.08
But 5.08 doesn't equal 508, so multiply 5.08 by 100.
100 is the same as 10^2

So the final answer would be:
5.08 * 10^2

kitty<3Jan 9, 2014

+5478

Well, you can use a calculator...

But if you mean how to divide w/out a calculator, then
divide in the same way as a regular number; just put the decimal point in the correct place.

For example,
0.246/2
would be
0/2 =0
*decimal point*
2/2 =1
4/2 =2
6/2 =3
So it would be 0.123

kitty<3Jan 9, 2014

Try this site
http://www.mathsisfun.com/algebra/exponent-fractional.html

GuestJan 9, 2014

+118725

Blake:
square root of 72000

Well you could just get an estimation from your calculator.
If you want to simplify it this is how it is done.
I'll do a different one and you can copy the technique, you will learn better that way.

sqrt(235200)
you have to look for square numbers that go into 235200.
square numbers are 1 (which doesn't help) ,4,9,16,25,36, etc
The most obvious one is 100
235200
= 100 * 2352 (now 4 goes into 2352)
= 100 * 4 * 588 (now 4 goes into 588 as well)
= 100 * 4 * 4 * 147 ( I can see straight off that 7 goes into 147, this isn't overly helpful but it gives me an idea to look at 49, and yes, 49 does go into 147)
= 100 * 4 * 4 * 49 * 3
So
sqrt(235200 )= sqrt( 100 * 4 * 4 * 49 * 3 ) = sqrt( 100 * 4 * 4 * 49 ) * sqrt3 => 10*2*2*7*sqrt3 => 280sqrt3
If you answer yours, I will check your answer if you want me too.

MelodyJan 9, 2014

+118725

You need to be more precise with what you are asking

MelodyJan 9, 2014

+118725

*
Now Professor,
Lilyahna asked exactly the same 1st question yesterday.
Only she wasn't cheeky enough to ask me or anyone else to do a whole page of homework for her.
Now I am wondering, are you and Lilyahna the same person

MelodyJan 9, 2014

Jan 8, 2014

-2.4

GuestJan 8, 2014

The answer is m = -2.4

GuestJan 8, 2014

no patrick,math is not an instrument

GuestJan 8, 2014

+10

Yeah sorry the 3/2 should be in brackets

davidashworth7Jan 8, 2014

Oh my ! I'm sorry, I knew I did something wrong but I was in a rush so I couldn't fix it. My apologies! Oh dear, I feel ridiculous now. A professor whom got an easy algebra questions wrong! Please forgive me and thank you Melody for correcting it. That would of been truly awful for hi,/her to have used any of our answers and to have gotten them wrong.

Professor R.LopezJan 8, 2014

Melody-

Thank you so much and yes I'm quite the happy camper right now. I've missed you so much as well! How was your Christmas and New Years? Do anything fun? Get anything you liked..?And lilyahna, you sound like a crazy person in my family..only way you couldn't be human or any of that such is if you are in fact and computer speaking or the Government is keeping mutants/clones away from the people today. Enough crazy talk, I don't know you but you could be some person trying to pretend and not use this website for math source related purposes. Have a good you too !

GuestJan 8, 2014

Hola cx

GuestJan 8, 2014

#73

1) You wanted to show me that I need to improve reading the questions
2) So this will help me understand more compound interest more.
3) To see the relationships between the question you gave me earlier and these

GuestJan 8, 2014

#40

(2+7)*100+50+3

Use these numbers to make the number 953.

Rules:
Use only these numbers
No number can be used twice
You do not have to use all the numbers
You can use + - x or divide.
You can use brackets.

First one to respond with exact answer wins. If you post later but you have a substantially different answer, you win too.
If no-one gets the exact answer then closest answer after 12 hours wins. (competition closes in 12 hours)

You will be expected to explain how you got your answer.

Use a name other than 'guest' and your wins will be recorded.
If enough people are interested we will keep playing with different numbers.
Any questions?
(I have copied this game from the TV show 'Letters and numbers')
Have fun.
[/quote]

GuestJan 8, 2014

Sorry in advance for my english, it's not perfect and I might make some grammar mistake
First, i forgot to mention that the result should be [0.270842].

You are d**n right I did the right reasoning, but I made some calculation errors (shame on me, you do not study mathematics at night!)
To apologize i'll post the solved exercize so it's avaible to other users.

Since they are repeated tests, you will have to apply Bernoulli:
P=nCr(n.k)*p^k*(1-p)^(n-k)
where, in this case, n=25 b***s, p=16/25 (possibilities to pick a white ball) and k is the number of the white b***s i am supposed to pick.

There are two ways to solve this:
1) To add P(0), P(1), P(2), P(3), P(4), P(5)
2) P=1-P(6)-P(7)-P(8)-P(9)-P(10)

Let's pick the first one. We need to apply Bernoulli to every case (no white b***s picked, 1 white ball picked, 2 white ball picked etc.)
P(0)= nCr(10,0)*(16/25)^0*(1-16/25)^10 = 0.0000365615844006
P(1) = nCr(10,1)*(16/25)^1*(1-16/25)^9 = 0.0006499837226779
P(2) = nCr(10,2)*(16/25)^2*(1-16/25)^8 = 0.0051998697814229
P(3)= nCr(10,3)*(16/25)^3*(1-16/25)^7 = 0.0246512345193382
P(4)= nCr(10,4)*(16/25)^4*(1-16/25)^6 = 0.0766927296157188
P(5) = nCr(10,5)*(16/25)^5*(1-16/25)^5 = 0.1636111565135335

We need to keep in mind that the events are incompatibles (if i pick 1 ball, i con't pick2 at the same time) and unconditioned (if i pick a ball and i put it again in the urn, the ball number will always be the same). The probability that less than 6 b***s are white is obtained adding the calculated probabilities between them:
P= 0.0000365615844006+0.0006499837226779+0.0051998697814229+0.0246512345193382+0.0766927296157188+0.1636111565135335 = 0.2708415357370919 = 0.270842

And here you go thanks melody

GuestJan 8, 2014

#39

+118725

Now our scores are
gb4242. (1 win - 10points)
Jedithious (1 win- 10 points)
Kitty (2 wins - 20 points)
Warped Tour Girl (2 win - 20 points)
Puzzled (2 wins - 20 points)
(if there is any errors in the totals let me know and I will try to sort it out)

New puzzle PUZZLE 7
2,6,3,10,50,9 Magic number is 287

You are only allowed to use brackets, +, -, x, and divide.
You can only use the numbers given, you can't use the same number twice but you don't have to use all of the numbers.
The magic number is the total.
If you get the answer try to describe how you worked it out. They are much easier when you start getting some techniques.

Have fun

MelodyJan 8, 2014

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