LCM( 14, 28 ) = 28
The formula for finding LCM is
$$ \text{LCM} (a, b) = \frac{ a \cdot b }{ \text{GCD}(a,b)} $$In this example we have: a = 14, b = 28 and GCD(14, 28) = 14.
$$ \text{LCM} (14, 28) = \frac{ 14 \cdot 28 }{ \text{GCD}(14,28)} = \frac{ 392 }{ 14 } = 28 $$