9514 1404 393
Answer:
a. numbers: 24, 210
b. GCF = 6
c. LCM = 840
Explanation:
The number each circle represents is the product of the factors in that circle:
red circle: 2×2×2×3 = 24
blue circle: 2×3×5×7 = 210
The numbers represented in the diagram are 24 and 210.
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The GCF is the product of the common factors--the factors in the portion of the diagram where the circles overlap:
GCF = 2×3 = 6
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The LCM is the product of all of the factors shown in the diagram:
LCM = 2×2×2×3×5×7 = 840
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Additional comment
I personally find this a nice way to represent two numbers, their GCF, and their LCM. Note that there cannot be any numbers in the red (only) part of the diagram that are also in the blue (only) part of the diagram. Any common factors belong in the overlap portion of the diagram.
This diagram makes it easy to see that the LCM is the product of the numbers, divided by their GCF. (The product of the two numbers will have the center portion of the diagram appear twice in the product. It only appears once in the LCM.)