Calculating LCD and GCD of 2 Sets of Numbers

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SUMMARY

The discussion focuses on calculating the greatest common divisor (GCD) and least common multiple (LCM) of two sets of numbers using their prime factorizations. The GCD of the numbers \(2^4 \cdot 3^2 \cdot 5 \cdot 7^2\) and \(2 \cdot 3^3 \cdot 7 \cdot 11\) is determined to be \(2 \cdot 3^2 \cdot 7\). The LCM of \(2^3 \cdot 3^2 \cdot 5\) and \(2 \cdot 3^3 \cdot 7 \cdot 11\) is calculated as \(2^3 \cdot 3^3 \cdot 5 \cdot 7 \cdot 11\). The discussion emphasizes the importance of understanding prime factorization for these calculations.

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karush
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Determine
$\textit{gcd}(2^4 \cdot 3^2 \cdot 5 \cdot 7^2,\quad 2 \cdot 3^3 \cdot 7 \cdot 11)$
and
$\textit{lcm}(2^3 \cdot 3^2 \cdot 5,\quad 2 \cdot 3^3 \cdot 7 \cdot 11)$

ok the example appeared to have combine the 2 sets on gcd but I am still ?

there is no book answer for this:confused:
 
Last edited:
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Greatest Common divisor ... think about how you would factor out the common terms from both prime decompositions if they were added

$(2^4 \cdot 3^2 \cdot 5 \cdot 7^2) + (2 \cdot 3^3 \cdot 7 \cdot 11)$

${\color{red}(2 \cdot 3^2 \cdot 7)} \bigg[(2^3 \cdot 5 \cdot 7)+ ( 3 \cdot 11) \bigg]$Least Common Multiple ... think about obtaining a common denominator if both prime factor decompositions were denominators of two fractions

$\dfrac{x}{2^3 \cdot 3^2 \cdot 5} + \dfrac{y}{2 \cdot 3^3 \cdot 7 \cdot 11}$

$\dfrac{x(3 \cdot 7 \cdot 11) + y(2^2 \cdot 5)}{\color{red} 2^3 \cdot 3^3 \cdot 5 \cdot 7 \cdot 11}$
 
well that makes a lot more sense

i don't think there is any need to multiple these out:cool:
 
Last edited:

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