Solve Absolute Value.
|6x + 3| = 15
We know either 6x + 3 =15 or 6x + 3 = −15
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6x + 3 = 15 (Possibility 1)
6x + 3 - 3 = 15 − 3 (Subtract 3 from both sides)
6x = 12

x = 2
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6x + 3 = −15 (Possibility 2)
6x + 3 - 3 = -15 - 3 (Subtract 3 from both sides)
6x = -18

x = -3
Therefore, the answer is x = 2 or x = −3. The correct option is alternative "D".