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**silverpuma****Member**- Registered: 2011-06-19
- Posts: 80

https://www.dropbox.com/s/sn00ksxbx9hn6 … 193709.jpg

Hi guys, I'm on standard form now and got all my exam type questions from the text book right until this last one (see above) the answer is 2167 seconds as per the answer sheet but could you show your working out for me as I must be making a wrongs step along the way. Thanks as always

Ooops it question 4 the planets

*Last edited by silverpuma (2014-04-10 06:56:01)*

Men occasionally stumble over the truth, but most of them pick themselves up and hurry off as if nothing ever happened. ― Winston Churchill

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 103,783

Hi;

Now you do them one parentheses at a time.

The next one is really simple you just subtract exponents ( powers ) 11 - 8 = 3.

Now 2.166666 x 10^3 just means move the decimal point 3 places to the right. We get 2166.666. Now 2166.666 is closer to 2167 than it is to 2166 so we round up. Answer is 2167 s.

Of course there is a rule about rounding up and down but we do not need it here.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.** **A number by itself is useful, but it is far more useful to know how accurate or certain that number is.**

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**silverpuma****Member**- Registered: 2011-06-19
- Posts: 80

Great bobbym all makes sense now. I could kick myself not getting this right but the learning goes on. Irrational and rational numbers next with surds after that yum yum. Thanks for the help....

Men occasionally stumble over the truth, but most of them pick themselves up and hurry off as if nothing ever happened. ― Winston Churchill

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 103,783

Soon you will get to Absolute value and Surds, then they will combine an Absolute value and a Surd into AbSurd. Just a little geek humor.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.** **A number by itself is useful, but it is far more useful to know how accurate or certain that number is.**

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**silverpuma****Member**- Registered: 2011-06-19
- Posts: 80

bobbym wrote:

Soon you will get to Absolute value and Surds, then they will combine an Absolute value and a Surd into AbSurd. Just a little geek humor.

He he.....

Even the name "surds" who thought that one up......

Men occasionally stumble over the truth, but most of them pick themselves up and hurry off as if nothing ever happened. ― Winston Churchill

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 103,783

Hi;

I have no idea.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.** **A number by itself is useful, but it is far more useful to know how accurate or certain that number is.**

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