The answer is: 1, 2, 7, 14 .
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Step-by-step explanation:
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FIrst, list all the factors of 42 (positive integers):
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1, 42
2, 21,
3, 14,
6, 7
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Then list all the factors of 28 (positive integers):
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1, 28
2, 14,
4, 7
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Now, list all numbers that occur for BOTH the factors of "28" AND the factors of "42"
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1, 2, 7, 14
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The answer is: 1, 2, 7, 14 .
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