The 2 absolute equation equality? find the max and min of x?

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Homework Help Overview

The discussion revolves around finding the maximum and minimum values of x based on the inequalities derived from the equation 2x - 1 and x - 2. Participants are analyzing the conditions under which these inequalities hold true and how they affect the values of x.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants present various cases based on the inequalities, attempting to solve for x in different intervals. Questions arise regarding the validity of solutions, particularly in the case where x is assumed to be greater than or equal to 2.

Discussion Status

There is an ongoing examination of the proposed solutions, with some participants questioning the correctness of the original poster's conclusions. A contradiction is noted in one of the cases, prompting further clarification and discussion about the correct maximum and minimum values.

Contextual Notes

Participants reference a "key answer" that differs from the values initially proposed, indicating a potential misunderstanding or miscalculation in the original attempts. The discussion highlights the importance of careful verification of solutions in the context of the inequalities presented.

Helly123
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Homework Statement


15_Mat_B_-_1.6.png


Homework Equations

The Attempt at a Solution


2x - 1 >= 0
x >= 1/2

x - 2 >= 0
x >= 2

for x <1/2
then 2x - 1 and x - 2 are negative
solve : -(2x-1) - (x-2) = 2
-3x + 3 = 2
x = 1/3

for 1/2 <= x < 2
the (2x - 1) positive, (x-2) negative
solve : 2x -1 -x + 2 = 2
x = 1

for x>= 2
both 2x -1 and x -2 = positive
2x - 1 + x - 2 = 2
3x = 5
x = 5/3

is my answer right? then the max of x is 5/3? and the min is 1/3?
 
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Helly123 said:

Homework Statement


View attachment 205815

Homework Equations

The Attempt at a Solution


2x - 1 >= 0
x >= 1/2

x - 2 >= 0
x >= 2

for x <1/2
then 2x - 1 and x - 2 are negative
solve : -(2x-1) - (x-2) = 2
-3x + 3 = 2
x = 1/3

for 1/2 <= x < 2
the (2x - 1) positive, (x-2) negative
solve : 2x -1 -x + 2 = 2
x = 1

for x>= 2
both 2x -1 and x -2 = positive
2x - 1 + x - 2 = 2
3x = 5
x = 5/3

is my answer right? then the max of x is 5/3? and the min is 1/3?
These are the values I get, as well.
 
Mark44 said:
These are the values I get, as well.
so what's the max and min of x? because the key answer not 1/3 and 5/3. but 1/3 and 1
 
Your third case is self-contradictory. On the assumption that x >= 2, you get x = 5/3, which is < 2. So this case is ruled out, and the answers are 1/3 and 1.
 
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Helly123 said:
so what's the max and min of x? because the key answer not 1/3 and 5/3. but 1/3 and 1
mjc123 said:
Your third case is self-contradictory. On the assumption that x >= 2, you get x = 5/3, which is < 2. So this case is ruled out, and the answers are 1/3 and 1.
Yes, @mjc123 is correct. I wasn't careful enough in checking my solutions. The maximum value is x = 1.
 

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