Answer:
x = 12
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Subtract 6x from both sides.
2x + 39 - 6x = 6x - 9 - 6x
-4x + 39 = -9
Subtract 39 from both sides.
4x + 39 - 39 = -9 - 39
-4x = -48
Divide both sides by -4.
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x = 12