LCM( 1296, 2520 ) = 45360
The formula for finding LCM is
$$ \text{LCM} (a, b) = \frac{ a \cdot b }{ \text{GCD}(a,b)} $$In this example we have: a = 1296, b = 2520 and GCD(1296, 2520) = 72.
$$ \text{LCM} (1296, 2520) = \frac{ 1296 \cdot 2520 }{ \text{GCD}(1296,2520)} = \frac{ 3265920 }{ 72 } = 45360 $$