Josefina stopped at Step 3 because she realized that her manipulation of the equation had resulted in a sign error. Let's review the steps:
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The original equation is: \[ 3.5 = 1.9 - 0.8|2x - 0.6| \]
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In her first step, it appears she mistakenly interpreted the absolute value and began solving without considering the necessary cases for absolute values. Moreover, she went directly to Step 1 as: \[ 3.5 = 1.9 - 0.8(2x - 0.6). \]
This is not correct since she ignored the property of the absolute value.
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In Step 2, she simplified: \[ 1.6 = -0.8(2x - 0.6), \] which is correct based on her previous line.
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However, in Step 3, she arrived at: \[ -2 = 2x - 0.6. \] This step might lead her to think of isolating \(x\), but it isn't the correct approach due to the sign of the absolute value not being considered.
At this point, Josefina likely realized that she needed to properly address the absolute value in the equation. The absolute value \( |2x - 0.6| \) splits into two cases:
- \( 2x - 0.6 = k \) where \( k \geq 0 \)
- \( 2x - 0.6 = -k \) where \( k < 0 \)
By stopping at Step 3, she may have recognized the need to return to the original equation and consider these cases before proceeding any further, ensuring a complete solution rather than one that could lead to incorrect results.