2/3[(5+3)^2-31]

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OK.....let's simplify things a bit   we have

(2/3) [8² -31]

(2/3) [64 - 31]

(2/3)[33]

66/3

22

is 1/3 15/27

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Here's a method to determine whether two fractions are equal.......just cross-multiply.....if the products are equal, then the fractions are equal!!

So........1x27 = 27       3 x 15 = 45    Nope!!!

"Reducing"  15/27 gives us 5/9 !!

By the way.....look at these fractions closely.....isn't 15 more than 1/2 of 27???   So there's no way that 15/27 = 1/3, as we can determine just by examination....

Re: Kako se racuna zapremina?

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Budi precizniji ...... volumen kakav predmet (ili oblik?)

(Be more specific......the volume of what object (or shape??))

if julie runs seven miles each day except for sundays, how many miles will she have ran in three months?

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Well....depending on the months, let's just say that a three month period lasts 90 days.

Let's let her begin running on a Monday.

Note that 90 days = (13 weeks - 1 day).

So she runs 13 weeks x 6 days per week x 7 miles per day = 13 x 42 = 546 miles.

Notice, that in the last week, Sunday would be the 91st day....but she doesn't run on that day, anyway.

what is the nth rule for this sequence/ 4,10,16,22?

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a_n = 4 + 6(n-1)   = 6n - 2   where "n" is the n^th term

Re: how do i solve 2 1/4 x 3 2/3 ----------------------------------------------------------------------------------------------------------------------------

Let's convert each mixed number to an improper fraction.......we have

9/4 x 11/3      Notice that we can "cross-cancel" the "9" with the "3"      This gives us

3/4 x 11/1 = 33/4 = 8 1/4

It's always nice if you can "cancel" before you multiply....it usually saves some work, later

Also, you could use the on-site calculator to do this...just make sure that you put parentheses around both mixed numbers.  The calculator will give you the answer in both fractional and "mixed form" - if the result has a "mixed form."

don't forget about complex numbers. There is no solution only for real numbers

Mean Average = (4+11+7+3+10+5+2+1)/8 = 5.375 = 43/8

Hope this helps!

If y=2x + 1/3,

x=2y + 1/3

2y=x - 1/3

y=(x - 1/3)/2

Inverse: (y=) x/2 - 1/6

If y=(2x+1)/3,

x=(2y+1)/3

3x=2y+1

2y=3x-1

Inverse: y=(3x-1)/2

Hope this helps!

356/2=178

Middle pages=178-179

sin2x=3/2

sin2x=1.5

Since -1<sin2x<1, there are no solutions for x.

*By <, I actually mean the sign "less than or equal to" (I haven't learned how to type that symbol yet).

1. A calculator makes life much easier, as complex functions can be now done within a fraction of a second without thinking.

2. This means that we humans can now achieve more than our ancestors as we can now calculate much more complex functions.

3. Our lives will be better as improved mathematical "facilities" and tools mean that better things are being invented.

4. Therefore the society improves both mathematically and in other ways.

Hope this helps!

7:30 - 10:30 = 10.5-7.5=3 hrs

10:20 = 10 minutes earlier = 10:30 - 10 mins

3 hrs - 10 mins = 2 hrs 50 mins

Deleted Deleted

think about it

6:40 to 8:40 That's 2 hours

8:40 to 8:55 that is 15 minutes. 

hence 2 hours and 15 minutes.  

Thanks Alan,

Thanks for the address too - it is a really good idea to reference posts like this.  

I used the link and examined your previous post and I would have arrived at the same answer but I have always maintained that there are differerent levels of understanding.  

I think Chris and I both  accept this answer but I think I only understand it at a superficial level.

Is there anything you can say that will help?  Maybe I just need to think about it and work through a few different shapes to cement an understanding.  Yes, that should work.

Don't worry, I am just thinking with my fingers.  

Thanks David.  

There ARE a lot of them.

The following site lists countries by their number format system

@@ End of day wrap - Sunday 27/4/14   Sydney, Australia Time 20:33

Hi everyone,

I am using a new heading - I am hoping that it will stand out better in the forum.

Another busy day with lots of fantastic answers from Mathwizard91472, CPhill, Bioschip, garanceme, Alan, DavidQD, Bertie, and 1or 2 anonymous people.  A big thank you to all of you.  

There was only one unanswered question on the forum and I am sure Chris will have answered it by the time I finish this post.  Andre, Chris has got his eye on the admin score on the 'Top Answerer' board, it shouldn't take him too long to over take! Then it will be my turn to worry. lol

There were also a couple of nice thank yous given today,  all answerers really appreciate it when people show their gratitude.  

I like this question today.  It made me think.  Chris and I both invite more comment.

This one also generated interest.

Chris has told me that sometimes these links don't work.  There are still a lot of teething problems on the new forum.  I think they usually work though. So good luck.

That is it for this lovely Saturday/Sunday

I don't know why it is lovely - I am just in a good mood. 

Melody.        

melodymathforum@gmail.com

Yes, you are correct.  I answered a similar question a couple of days ago

 http://web2.0calc.com/questions/the-volumes-of-two-mathematically-similar-solids-are-in-the-ratio-27-125-the-surface-area-of-the-smaller-solid-is-36cm-2-work-out-the-surfa#r102051

To be honest, I kinda' struggled with it, too. I don't "do" 3-D as well as "2-D," so if I can lay something out in terms of area, it usually helps me see its volume....basically, my answer was just me "thinking aloud!!!" I believe it's correct, but  Alan, Rom or Bertie  - or someone else - might verify it (or not)!!!

Assuming they're in the same time zone - and I think they are...... 2 hrs 15 min

Thanks Chris,

Our anonymous enquirer should change it to a mixed numeral i think.

I really like the way you explain these questions Chris.  I probably should try to adopt a similar method. 

Thanks Chris,

I was struggling with this question.  

I guessed that  

$$V=540\times\left(\sqrt{\frac{1600}{900}}\right)^3$$

but you helped me understand why this is correct.

If anyone else would like to put another take on it i would be very interested. 

Re: 4a+5b=7,b=8

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This says we are just letting b=8 and then trying to find "a"

OK....so

4a + 5(8) = 7

4a + 40 = 7    subtract 40 from both sides

4a = -33          divide both sides by 4

a = -33/4

That's it !!   You should check this answer in the original equation to make sure it's true.