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#1 2016-12-22 12:03:45

Hannibal lecter
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Registered: 2016-02-11
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hi, any help with these two question?

hello
I tried to solve these two question about absolute value inequality but I stuck with x^2 and with number 2

please see this picture and solve this two for me,  the answer of my teacher for 1) is (-∞,1] U [9,∞)

and for 2) is (-∞,∞)

is it right?


I tried the a way that a member learned me that here but I stuck

solve this in short way for me please!!! it takes me 3 days and I didn't find any solution :

1482451359491.jpg[URL="http://www.up-0

Last edited by Hannibal lecter (2016-12-22 12:07:58)


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#2 2016-12-22 12:31:28

Hannibal lecter
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Re: hi, any help with these two question?

these I'm while I'm trying to solve it myself :

like I said I stuck because of x^s and I stuck because of number 2 in the second question...

1482452951651.jpg


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#3 2016-12-22 14:13:14

bobbym
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From: Bumpkinland
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Re: hi, any help with these two question?

Hi;

For 1) that should be


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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#4 2016-12-22 14:34:53

Hannibal lecter
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Re: hi, any help with these two question?

yes and what is the next

I mean I stuck in this point,,, what I have to do now?  please I want full solution I really have an exam after one week in such topics..

Last edited by Hannibal lecter (2016-12-22 15:16:43)


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#5 2016-12-22 15:25:03

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

Re: hi, any help with these two question?


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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#6 2016-12-23 06:37:23

Hannibal lecter
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Registered: 2016-02-11
Posts: 146
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Re: hi, any help with these two question?

I think yes,  maybe

x-9 ≥ 0 =>>>>>>>>>  x≥9 then [9,∞)
and x-1≥0 =>>>>       x≥1    then [1,∞)

sol : [9,∞] U [1,∞)

is that right??  but the answer of my teacher is different???,



by the way thank you for this link I study the factors and quadratic equations,


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#7 2016-12-23 06:40:11

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

Re: hi, any help with these two question?

Hi;

The answer of your teacher is different because yours is not correct.  Did you read the links thoroughly, they show how to do this.


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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#8 2016-12-23 07:49:57

Hannibal lecter
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Registered: 2016-02-11
Posts: 146
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Re: hi, any help with these two question?

I was study factoring and Quadratic Equations but I just started to study (Solving Quadratic Inequalities),

and I stuck with the first example,, I'll finish it...


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#9 2016-12-23 08:00:28

Hannibal lecter
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Registered: 2016-02-11
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Re: hi, any help with these two question?

I finish the first link math isfun.com

is the sol :  : [9,∞] ∩ [1,∞)

not U?

and if yes why ∩????

is cause will be either the first interval or the second one??

please I need answers I get board from trying I have a lot of topics in maths to finish sad

Last edited by Hannibal lecter (2016-12-23 08:01:24)


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#10 2016-12-23 08:22:44

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

Re: hi, any help with these two question?

Hi;

I do not use that set notation but I am getting:

The area you want is colored purple.

5H3vkVM.png


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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#11 2016-12-23 08:43:01

Hannibal lecter
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Registered: 2016-02-11
Posts: 146
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Re: hi, any help with these two question?

but how that can be? x<= 1??

if we put -3 in it will be |-3+3| , zero,, and that is wrong right?

how did you do that

Last edited by Hannibal lecter (2016-12-23 08:43:36)


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#12 2016-12-23 09:09:16

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

Re: hi, any help with these two question?

Hi;

if we put -3 in it will be |-3+3| , zero,, and that is wrong right?

That is correct. I think you should point that out to your teacher.


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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#13 2016-12-23 09:18:10

Hannibal lecter
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Registered: 2016-02-11
Posts: 146
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Re: hi, any help with these two question?

sure,,,  but what is the right answer now?


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#14 2016-12-23 09:19:01

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

Re: hi, any help with these two question?

Same as before just state that


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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#15 2016-12-23 09:28:09

Hannibal lecter
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Registered: 2016-02-11
Posts: 146
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Re: hi, any help with these two question?

I mean how do you solve this ? what is the steps do it here please


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#16 2016-12-23 09:38:05

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

Re: hi, any help with these two question?

1) Find the zeros.

2) Plot them on the number line.

3) Pick a point or points to get the interval you want.


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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#17 2016-12-23 09:47:36

Hannibal lecter
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Registered: 2016-02-11
Posts: 146
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Re: hi, any help with these two question?

I'll show you what I did,,,

when (x-9) (x-1) ≥ 0
(x-9) = 0 , x=9 the interval is [9,∞) , test a value between this interval : "10" : 10^2 - 10*10 +9 ≥ 0  , +9 ≥ 0  and that is true!
(x-1) ≥ 0 x=1 the interval is [1,∞) , test a value between this interval : "2" : 2^2 - 10*2 +9 ≥ 0 , -7 ≥ 0 , and that is WRONG! so Switch this inequality and become : x ≤ 1 ,  the  interval is : (-∞,1]

sol : (-∞,1] U [9,∞), except -3

is that ok? hehehe

Last edited by Hannibal lecter (2016-12-23 09:51:48)


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#18 2016-12-23 10:00:27

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

Re: hi, any help with these two question?

I have not done any of these in 83 years, so forgive me, I am beyond rusty. That is how I would phrase 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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#19 2016-12-23 10:09:07

Hannibal lecter
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Registered: 2016-02-11
Posts: 146
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Re: hi, any help with these two question?

that is ok I'm keeping on, thank you


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#20 2016-12-23 10:20:47

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

Re: hi, any help with these two question?

Okay, work on the next one.


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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#21 2016-12-23 10:23:57

Hannibal lecter
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Registered: 2016-02-11
Posts: 146
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Re: hi, any help with these two question?

I try it, it is [9,∞)

and  maybe (-∞,9], but I can't chose that one cause it is consist number 3 which make the denominator zero and I'll point this to the teacher,...

please can you give me the end of sol that you get it????


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#22 2016-12-23 10:29:44

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

Re: hi, any help with these two question?

Are you sure you have copied the problem correctly?


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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#23 2016-12-23 11:28:45

Hannibal lecter
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Registered: 2016-02-11
Posts: 146
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Re: hi, any help with these two question?

sorry I don't understand what is copied


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#24 2016-12-23 11:43:35

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

Re: hi, any help with these two question?

Hi;

Are you sure you copied the problem down correctly for #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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#25 2016-12-23 11:46:26

Hannibal lecter
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Registered: 2016-02-11
Posts: 146
Website

Re: hi, any help with these two question?

yes of course

but for the end of sol I don't know what is the truth 100% the sol of teacher or min

anyway I need you solution cause it is always true when you are using the graph

to make sure I'm point to my teacher with a correct information


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