Math Is Fun Forum

EbenezerSon

Member

Registered: 2013-07-04

Posts: 554

Re: Simplify the following:

I was thinking of using the formula; -b positive or negative,  square root of b^2 - 4ac/2a

Last edited by EbenezerSon (2014-08-28 06:11:10)

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I know only one thing - that is that I know nothing

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Simplify the following:

That is correct! You will get,

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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.

EbenezerSon

Member

Registered: 2013-07-04

Posts: 554

Re: Simplify the following:

Please I think these are correct,
a = 1, b = -2, c = -1 Before you will plug them in.

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I know only one thing - that is that I know nothing

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Simplify the following:

Those are correct for the plugging in.

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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.

EbenezerSon

Member

Registered: 2013-07-04

Posts: 554

Re: Simplify the following:

Thank you very much Bobbym! I will post another perhaps tommorow, finally finally if so then,  the answers must be two as you have shown above

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I know only one thing - that is that I know nothing

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Simplify the following:

The y's in post #352 are changed to 2^x and solved for.

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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.

EbenezerSon

Member

Registered: 2013-07-04

Posts: 554

Re: Simplify the following:

I did not put the question well, I meant the answers will be multiple answers

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I know only one thing - that is that I know nothing

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Simplify the following:

You mean two roots from the quadratic equation? Yes, there will be two answers for y.

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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.

EbenezerSon

Member

Registered: 2013-07-04

Posts: 554

Re: Simplify the following:

The y's in post #352 are changed to 2^x and solved for.

I guess if one use 2^x  still factorisation is impossible unless the quadratic formula. What do you say?

THANK YOU BOBBYM, GOD BLESS!!!

Last edited by EbenezerSon (2014-08-28 06:57:03)

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I know only one thing - that is that I know nothing

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Simplify the following:

You are correct you can not factor that easily so you use the quadratic formula. try to get it on your own.

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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.

EbenezerSon

Member

Registered: 2013-07-04

Posts: 554

Re: Simplify the following:

I had 2.4142 and -0.4142 as the answers,  is these correct?
Please confirm.

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I know only one thing - that is that I know nothing

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Simplify the following:

Yes, those are correct. You could have derived the exact answers though.

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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.

EbenezerSon

Member

Registered: 2013-07-04

Posts: 554

Re: Simplify the following:

Thank you Bobbym!

These are the possible answers to the question; A. 13 B. 19 C. 25 .D 37

If X + 6/X = 5 find the value of X^2 + 36/X^2

I had 10 and 13 as the answers but I am wondering as to why it has only 13 in the possible answers, can you explain why?

Last edited by EbenezerSon (2014-08-28 23:54:41)

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I know only one thing - that is that I know nothing

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Simplify the following:

10 is not an answer but 13 is.

Solve the first quadratic and you will see why.

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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.

EbenezerSon

Member

Registered: 2013-07-04

Posts: 554

Re: Simplify the following:

Errr, I see, I miscalculated it. Both 2 and 3 when plug in give 13

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I know only one thing - that is that I know nothing

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Simplify the following:

That is correct.

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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.

EbenezerSon

Member

Registered: 2013-07-04

Posts: 554

Re: Simplify the following:

Again,

2^2x - 2 . 2^x - 8 = 0

I had 1 and 2 as answers, but the book has only 2 as the answer.

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I know only one thing - that is that I know nothing

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Simplify the following:

Is that 1 equation?

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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.

EbenezerSon

Member

Registered: 2013-07-04

Posts: 554

Re: Simplify the following:

In fact, this is the original question;

Find the value of X in following equation.

2^(2x-3) - 2^(x-2) - 1 = 0

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I know only one thing - that is that I know nothing

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Simplify the following:

Try to get all those terms to look like 2^x, that should work.

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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.

EbenezerSon

Member

Registered: 2013-07-04

Posts: 554

Re: Simplify the following:

I have done it, but this is a part of mine

(m +2) (m - 4) = 0
Let m = 2^x)
m = -2
2^x = -2 = -1 is this correct?

m = 4
2^x = 2^2 = 2

Last edited by EbenezerSon (2014-08-29 00:58:53)

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I know only one thing - that is that I know nothing

EbenezerSon

Member

Registered: 2013-07-04

Posts: 554

Re: Simplify the following:

I am wondering if that negative one [-1] is correct.

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I know only one thing - that is that I know nothing

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Simplify the following:

That factorization does not look correct.

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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.

EbenezerSon

Member

Registered: 2013-07-04

Posts: 554

Re: Simplify the following:

This is my factorization
m^2 - 2m - 8 = 0
m^2 - 4m + 2m - 8 =0
m(m -4) 2(m - 4) = 0
(m + 2)(m - 4) = 0
let m = 2^x
m + 2 = 0
m = -2
2^x = -2 = -1 is this answer correct?

m -4 = 0
m = 4
2^x = 4 = 2^2 = 2
And are you saying it is wrong?

Last edited by EbenezerSon (2014-08-29 04:46:06)

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I know only one thing - that is that I know nothing

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Simplify the following:

That looks okay now.

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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.