Calculating the least common multiple of $n$ numbers, knowing the LCM of $(n-1)$ of them

Question

I know the value of LCM($a_1, a_2, ..., a_{n - 1}$) How can I use this information to calculate LCM($a_1, a_2, ..., a_{n}$)?

Answer 1

By using the fact that $$ \def\l{\operatorname{lcm}}\l(a_1, \ldots, a_n) = \l\bigl(\l(a_1, \ldots, a_{n-1}), a_n\bigr) $$