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#151 2010-10-15 06:35:39
- misheeru
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- Registered: 2010-02-18
- Posts: 4,594
Re: Equations with parenthesis?
Oh, sorry to wake you! 
Okay so:
3y + 2 ≥5y +8
/\
3y - 5y ≥ -2 + 8
/\
3y - 5y ≥ 6
/\
-2y ≥ 6
Okay, before I go any further, how is that?
Last edited by misheeru (2010-10-15 06:46:17)
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#152 2010-10-15 06:39:40
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Equations with parenthesis?
Okay, I meant treat the >= like an equals not replace it. Please go back and put the >= for the equals sign.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#153 2010-10-15 06:46:35
- misheeru
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Re: Equations with parenthesis?
thar ya go. is that better?
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#154 2010-10-15 06:47:42
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Equations with parenthesis?
Now how do you get y by itself?
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#155 2010-10-15 06:50:10
- misheeru
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Re: Equations with parenthesis?
By dividing -2y by -2?
-2y ≥ 6
-2/ -2y ≥ 6/-2
y ≥ -3
like that?
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#156 2010-10-15 06:52:39
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Equations with parenthesis?
Be careful of your notation.
This is wrong! -2/ -2y ≥ 6/-2
This is right! (-2y)/-2 ≥ 6/-2
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#157 2010-10-15 07:03:21
- misheeru
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- Registered: 2010-02-18
- Posts: 4,594
Re: Equations with parenthesis?
oh, right! okay so we have
(-2y)/-2 ≥ 6/-2
y ≥ -3 was written correctly though, right?
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#158 2010-10-15 07:07:32
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Equations with parenthesis?
Now there is a rule:
Whenever you divide or multiply an inequality by a negative number then you reverse the greater than or less than sign.
Remember you divided by - 2.
So ≥ becomes ≤
The answer is.
y ≤ -3
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#159 2010-10-15 07:08:36
- misheeru
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- Registered: 2010-02-18
- Posts: 4,594
Re: Equations with parenthesis?
Ohh. Okay I will remember that.
Just out of curiosity, why do we do that?
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#160 2010-10-15 07:14:46
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Equations with parenthesis?
In short, so that we get the right answer. Look at this:
5 > 2
Read 5 is greater than 2. Do you agree?
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#161 2010-10-15 07:16:12
- misheeru
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- Registered: 2010-02-18
- Posts: 4,594
Re: Equations with parenthesis?
Yes.
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#162 2010-10-15 07:17:16
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Equations with parenthesis?
Times both sides by 3:
3*5 > 3*2
15 > 6 Agreed?
Now times ( 5 > 2 ) both sides by -2.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#163 2010-10-15 07:24:41
- misheeru
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- Registered: 2010-02-18
- Posts: 4,594
Re: Equations with parenthesis?
Oh, I see that wouldn't work because
-10 > -4 is not true, right?
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#164 2010-10-15 07:27:03
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Equations with parenthesis?
That is right. Same thing for division which is actually multiplication in disguise.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#165 2010-10-15 07:29:23
- misheeru
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- Registered: 2010-02-18
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Re: Equations with parenthesis?
Craziness. There are so many things to remember! XD
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#166 2010-10-15 07:30:58
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Equations with parenthesis?
Well, you are young and can remember. besides you have an example now
(-10 > -4) to help you remember.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#167 2010-10-15 07:34:23
- misheeru
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- Registered: 2010-02-18
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Re: Equations with parenthesis?
you mean: (-10 < -4) right? 
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#168 2010-10-15 07:36:35
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Equations with parenthesis?
Yes, I only put it like that because we both know it is wrong. You will not forget that for a while.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#169 2010-10-15 07:38:25
- misheeru
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- Registered: 2010-02-18
- Posts: 4,594
Re: Equations with parenthesis?
Okie Doke. 
Thank you! You are a big help, as always.
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#170 2010-10-15 07:38:59
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Equations with parenthesis?
Glad to help. Have more?
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#171 2010-10-15 07:40:32
- misheeru
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- Registered: 2010-02-18
- Posts: 4,594
Re: Equations with parenthesis?
Yes, But I got them. I understand this pretty well now, I think.
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#172 2010-10-15 07:45:41
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Equations with parenthesis?
Good. So we are through for the day here?
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#173 2010-10-15 07:50:25
- misheeru
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- Registered: 2010-02-18
- Posts: 4,594
Re: Equations with parenthesis?
Yes. You should go in for that nappy now.
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#174 2010-10-15 07:52:56
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Equations with parenthesis?
Will do.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#175 2010-10-15 10:39:34
- misheeru
- Member
- Registered: 2010-02-18
- Posts: 4,594
Re: Equations with parenthesis?
Okay, see you later.
And to whatever else you have to do today, ganbatte ne
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