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44 votes
44 votes
2 |3x-5| - 4 = 12

Solve for x
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User Simon Thomsen
by
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1 Answer

25 votes
25 votes

Isolate the absolute-value term:

2 |3x - 5| - 4 = 12

2 |3x - 5| = 8

|3x - 5| = 4


Recall the definition of absolute value:


|x| = \begin{cases}x &amp; \text{if }x \ge0\\-x&amp;\text{if }x<0\end{cases}

We consider two cases:

• If 3x - 5 ≥ 0, then |3x - 5| = 3x - 5, and the equation resolves to

3x - 5 = 4

3x = 9

x = 3

• Otherwise, if 3x - 5 < 0, then |3x - 5| = -(3x - 5) = -3x + 5, hence

-3x + 5 = 4

-3x = -1

x = 1/3

User Nicolas Dudebout
by
3.3k points
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