LCM from Prime Decomposition/Examples/39, 102 and 75

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Example of Use of LCM from Prime Decomposition

The lowest common multiple of $39$, $102$ and $75$ is:

$\lcm \set {39, 102, 75} = 33 \, 150$


Proof

\(\ds 39\) \(=\) \(\ds 3 \times 13\)
\(\ds 102\) \(=\) \(\ds 2 \times 3 \times 17\)
\(\ds 75\) \(=\) \(\ds 3 \times 5^2\)
\(\ds \leadsto \ \ \) \(\ds 39\) \(=\) \(\ds 2^0 \times 3^1 \times 5^0 \times 13^1 \times 17^0\)
\(\ds 102\) \(=\) \(\ds 2^1 \times 3^1 \times 5^0 \times 13^0 \times 17^1\)
\(\ds 75\) \(=\) \(\ds 2^0 \times 3^1 \times 5^2 \times 13^0 \times 17^0\)
\(\ds \leadsto \ \ \) \(\ds \lcm \set {39, 102, 75}\) \(=\) \(\ds 2^1 \times 3^1 \times 5^2 \times 13^1 \times 17^1\)
\(\ds \) \(=\) \(\ds 33 \, 150\)

$\blacksquare$


Sources