LCM( 512, 768 ) = 1536
The formula for finding LCM is
$$ \text{LCM} (a, b) = \frac{ a \cdot b }{ \text{GCD}(a,b)} $$In this example we have: a = 512, b = 768 and GCD(512, 768) = 256.
$$ \text{LCM} (512, 768) = \frac{ 512 \cdot 768 }{ \text{GCD}(512,768)} = \frac{ 393216 }{ 256 } = 1536 $$