Bunuel
Does 8x = 16 + 2x?
(1) -3x is greater than or equal to -9.
(2) 2x is greater than or equal to 6.
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Target question: Does 8x = 16 + 2x?This is a good candidate for rephrasing the target question.
Take:
8x = 16 + 2xSubtract 2x from both sides:
6x = 16Divide both sides by 6 to get:
x = 16/6 = 8/3REPHRASED target question: Does x = 8/3? Statement 1: -3x ≥ -9 Divide both sides of the inequality by -3 to get:
x ≤ 3 [ since we divided both sides of the inequality by a negative value, we had to reverse the direction of the inequality symbol (see the video below for more on this)]If
x ≤ 3, it could be the case that x = 0, in which case the answer to the REPHRASED target question is
NO, x does not equal 8/3If
x ≤ 3, it could also be the case that x = 8/3, in which case the answer to the REPHRASED target question is
YES, x equals 8/3Since we can’t answer the
target question with certainty, statement 1 is NOT SUFFICIENT
Statement 2: 2x ≥ 6Divide both sides of the inequality by 2 to get:
x ≥ 3If
x ≥ 3, then x definitely can't equal 8/3 (since 8/3 < 3), which means the answer to the REPHRASED target question is
NO, x does not equal 8/3Since we can answer the
target question with certainty, statement 2 is SUFFICIENT
Answer: B
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