Absolute Value: Solve for x | MHB

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Discussion Overview

The discussion revolves around solving the equation $$||x|-2|+|x+1|=3$$. Participants explore different cases for the variable x to determine the correct solution set, focusing on the implications of absolute values in various intervals.

Discussion Character

  • Mathematical reasoning, Debate/contested

Main Points Raised

  • One participant presents the initial solution set $$x=0,-2,2,-1$$ but expresses uncertainty about the cases involved in the solution.
  • Another participant questions the correctness of the initial solution and suggests examining specific intervals for x, such as $$x<-2$$, $$-22$$.
  • A participant emphasizes the importance of checking the conditions $$\geq$$ or $$\leq$$ in the proposed intervals and suggests an alternative interval of $$-2
  • There is a note that the expression $$|x+1|$$ behaves differently at $$x=-1$$, which could affect the solution.
  • One participant indicates they have arrived at the correct answer after considering the feedback and checking the intervals.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the initial solution, and multiple competing views regarding the intervals and cases remain unresolved.

Contextual Notes

The discussion includes various assumptions about the behavior of absolute values in different intervals, but these assumptions are not fully resolved or agreed upon.

Petrus
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Hello MHB,
solve $$||x|-2|+|x+1|=3$$
and we find that $$x=0,-2,2,-1$$
I got problem to find the 'case',

Regards,
$$|\rangle$$
 
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Petrus said:
Hello MHB,
solve $$||x|-2|+|x+1|=3$$
and we find that $$x=0,-2,2,-1$$
I got problem to find the 'case',

Regards,
$$|\rangle$$

That doesn't look like the right solution...

Talking about cases, what if x<-2? Or -2<x<-1? And what about -1<x<0? Or perhaps 0<x<2? And x>2?
 
I like Serena said:
That doesn't look like the right solution...

Talking about cases, what if x<-2? Or -2<x<-1? And what about -1<x<0? Or perhaps 0<x<2? And x>2?
I don't mean those are the answer, but those are the point we should check $$\geq$$ or $$\leq$$, I hope you did understand.
Can I also check this one insted of -1<x<0
-2<x<0?

Regards,
$$|\rangle$$
 
Petrus said:
I don't mean those are the answer, but those are the point we should check $$\geq$$ or $$\leq$$, I hope you did understand.
Can I also check this one insted of -1<x<0
-2<x<0?

Sure you can. It's just that |x+1| does something funny at x=-1.
 
I like Serena said:
Sure you can. It's just that |x+1| does something funny at x=-1.
Thanks, got the correct answer now :)
Regards,
$$|\rangle$$
 

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