Answer: B. 2/3(x+6)
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Explanation:
If you distribute the expression in choice A, then you'd get
(1/3)(2x+6) = (1/3)*2x + (1/3)*6 = (2/3)x+2
which is not the original expression. So we can rule out choice A.
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A similar story happens with choice C
(2/3)(x+12) = (2/3)x+(2/3)*12 = (2/3)x+8
and also with choice D
(2/3)(x+4) = (2/3)x+(2/3)*4 = (2/3)x + 8/3
allowing us to rule out choices C and D
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Choice B works
(2/3)(x+6) = (2/3)x+(2/3)*6 = (2/3)x+4
