LCM( 5, 7 ) = 35
The formula for finding LCM is
$$ \text{LCM} (a, b) = \frac{ a \cdot b }{ \text{GCD}(a,b)} $$In this example we have: a = 5, b = 7 and GCD(5, 7) = 1.
$$ \text{LCM} (5, 7) = \frac{ 5 \cdot 7 }{ \text{GCD}(5,7)} = \frac{ 35 }{ 1 } = 35 $$