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#976 2011-01-19 18:31:54

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Equations with parenthesis?

We do not have to do anything with it. We have factored your problem.

This was your problem: 4x^2 + 12 xy + 9y^2

We have factored it!

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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#977 2011-01-19 18:35:49

misheeru
Member
Registered: 2010-02-18
Posts: 4,594

Re: Equations with parenthesis?

Oooh. I see that now.

But they want my to answer it in an (a + b)² or (a - b)² form, do I need to make any conversions or is (2x + 3y) alright?

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#978 2011-01-19 18:37:38

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Equations with parenthesis?

It is not (2x + 3y) it is (2x + 3y) ^2.

That is in an ( a + b )^2 form. a = 2x and b = 3y.

Now just one more thing, remember the 4?

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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#979 2011-01-19 18:38:38

misheeru
Member
Registered: 2010-02-18
Posts: 4,594

Re: Equations with parenthesis?

Oh! *facepalm* (forgot the ²)

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#980 2011-01-19 18:39:55

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Equations with parenthesis?

And remember the 4 you divided by in the beginning?

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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#981 2011-01-19 18:41:24

misheeru
Member
Registered: 2010-02-18
Posts: 4,594

Re: Equations with parenthesis?

Yes. It turned into 2, did it not?

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#982 2011-01-19 18:44:35

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Equations with parenthesis?

Nope!

The original problem was 16x^2 + 48 xy + 36y^2

So put it back by multiplying by 4:

This is the answer 4(2x +  3 y)^2

I suggest you FOIL this to check that we are right.

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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#983 2011-01-19 18:48:12

misheeru
Member
Registered: 2010-02-18
Posts: 4,594

Re: Equations with parenthesis?

Okay, but did we ever do any FOIL problems that had numbers outside of the parenthesis?

Do I treat 4 as the *F*?

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#984 2011-01-19 18:49:35

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Equations with parenthesis?

No, just ignore it and do the FOIL and then multiply everything by it.

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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#985 2011-01-19 18:55:40

misheeru
Member
Registered: 2010-02-18
Posts: 4,594

Re: Equations with parenthesis?

Okay.

*f* 2x * 2x = 4x²

*o* 2x * 3y = 6xy

*i* 2x * 3y = 6xy

*l* 3y * 3y = 9y²

= 4x² + 6xy + 6xy + 9y²

= 4x² + 36xy +  9y²

= (4)4x² + 36xy +  9y²

= 16x² + 36xy +  9y²

How does that look?

Last edited by misheeru (2011-01-19 18:56:27)

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#986 2011-01-19 18:59:00

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Equations with parenthesis?

That was darn close!

What the heck is this line here?

= 4x² + 36xy +  9y²

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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#987 2011-01-19 19:02:35

misheeru
Member
Registered: 2010-02-18
Posts: 4,594

Re: Equations with parenthesis?

LOL! That would be me... multiplying 6 and 6 instead of adding.

*f* 2x * 2x = 4x²

*o* 2x * 3y = 6xy

*i* 2x * 3y = 6xy

*l* 3y * 3y = 9y²

= 4x² + 6xy + 6xy + 9y²

= 4x² + 12xy + 9y²

= 4(4x² + 36xy +  9y²)

= 16x² + 36xy +  36y²

Better? Or darn closer?

Last edited by misheeru (2011-01-19 19:04:00)

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#988 2011-01-19 19:03:57

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Equations with parenthesis?

Correcta mundo! Now how about the correct workings.

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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#989 2011-01-19 19:04:21

misheeru
Member
Registered: 2010-02-18
Posts: 4,594

Re: Equations with parenthesis?

Check the edit. I edited it.

Last edited by misheeru (2011-01-19 19:04:37)

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#990 2011-01-19 19:06:53

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Equations with parenthesis?

That is darn closer!

= 4x² + 12xy + 9y²

= 4(4x² + 36xy +  9y²)

= 16x² + 36xy +  36y²

Step 1 is okay. Step 2, why is it now 36 xy? Step 3 is of course incorrect.

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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#991 2011-01-19 19:12:45

misheeru
Member
Registered: 2010-02-18
Posts: 4,594

Re: Equations with parenthesis?

Sorry! I somehow multiplied 3 and 12 instead of 4 and 12.

= 4x² + 12xy + 9y²

= 4(4x² + 12xy +  9y²)

= 16x² + 48xy +  36y²

But I am sure that 4 and 9 equal 36, so what I did wrong there is beyond me

Of Moons, Birds and Monsters

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#992 2011-01-19 19:14:25

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Equations with parenthesis?

You ended up with 36 xy instead of 48 xy that is what is wrong with line 3. Errors propagate throughout the work, they do not disappear.

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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#993 2011-01-19 19:16:57

misheeru
Member
Registered: 2010-02-18
Posts: 4,594

Re: Equations with parenthesis?

Oh! I though you were referring to 9 turning into 36 as step 3, I has about to ask how the heck 9 and 4 make 48! lol

Yes, I know. I will try to be more careful...

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#994 2011-01-19 19:17:30

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Equations with parenthesis?

Yes, you better or else!

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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#995 2011-01-19 19:18:40

misheeru
Member
Registered: 2010-02-18
Posts: 4,594

Re: Equations with parenthesis?

Okay!

Wait, or else what? You going to math me to death? I think your already doing that! lol

Last edited by misheeru (2011-01-19 19:19:17)

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#996 2011-01-19 19:19:56

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Equations with parenthesis?

You learned a lot today. We will do more of that type next time so that it will stick in your mind.

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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#997 2011-01-19 19:22:05

misheeru
Member
Registered: 2010-02-18
Posts: 4,594

Re: Equations with parenthesis?

Thank you! Couldn't have done it without you, of course!

Okay, are you leaving then?

Of Moons, Birds and Monsters

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#998 2011-01-19 19:22:35

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Equations with parenthesis?

Nope! I am forum man. If I leave I die.

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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#999 2011-01-19 19:24:34

misheeru
Member
Registered: 2010-02-18
Posts: 4,594

Re: Equations with parenthesis?

Well you said "next time", I assumed you were leaving!

Of Moons, Birds and Monsters

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#1000 2011-01-19 19:25:17

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Equations with parenthesis?

Marcus Penn wrote:

Assumption is the mother of all foul ups!

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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