LCM( 55, 143 ) = 715
The formula for finding LCM is
$$ \text{LCM} (a, b) = \frac{ a \cdot b }{ \text{GCD}(a,b)} $$In this example we have: a = 55, b = 143 and GCD(55, 143) = 11.
$$ \text{LCM} (55, 143) = \frac{ 55 \cdot 143 }{ \text{GCD}(55,143)} = \frac{ 7865 }{ 11 } = 715 $$