Absolute-Value Inequalities and Factoring

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School_girl

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Jun 6, 2005
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This is a very hard one. I just started Algebra 2, and from the begining have some difficulties. :( Would really appriciate your help..:) Okey, here is the link to the lesson...Can you explain it to me( i know it's not your job..but just please help..i really want to understand this). Thank you!!

http://www.purplemath.com/modules/absineq.htm
 
Okey, here are questions( don't think I am using you to do my homework...)

Find the absolute value inequality corresponding to the following:

[2, 10].

Solve the inequalities

And then 5 > |x| + 1

Okey, hang on one more..

absolute value of 7-2w/3 > 1( this is how I did it..) but it's wrong..

This is the pattern for this equation p<-b or p>b. So, absolute value of 7-2w/3 <-1 or 7-2w/3>1. 7-2w/3<-1( multiply each side by 3 and I get 7-2w<-3, then subtract 7 from both sides, -2w<-10. divide each side by -2, w<5. Other equation 7-2w/3>1, multiply each side by 3, 7-2w>3, subtract each side by 7, -2w>-4, divide each side by -2, the answer is w>2.
 
Nope..that'z what it said on the worksheet..I double checked..do you think it's teacher's mistake?
 
no its probably not the teachers mistake i only suggested it because on the link the questions were more like

5|x+1| rather than 5|x|+1 in fact i havent done much of this kind of work as yet i was just going to try and work from the link then offer my opinion

im pretty sure if thats whats on your sheet its correct.
 
i havent done this yet so if im wrong i apologise

i could even be completley off

if im wrong some with more expreience in this field will correct you im sure


5<|x|+1

-5>|x|+1>5

-5-1>|x|>5-1
 
What is the center of [2,10]? Is it 6?
What is the ‘diameter’ of the set? Is it 8? (10-2)=8.
So the radius is 4; thus |x-6|<4 is your answer.

In general, [a,b] has center (a+b)/2 and radius (b-a)/2.
So [a,b] is equivalent to |x-(a+b)/2|<(b-a)/2.

Now 5 > |x| + 1 is the same as 4>|x|, subtract 1.
Or –4<x<4.
 
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