Question

what is the easiest way to determine the lowest common denominator

Answer 1

Intuition, after a while you simply get good at it.

Answer 2

thanks a bunch

Answer 3

if the numbers are large the best way is to find the prime factors of each number and compare like factors

example:find lcm of 1025 and 625

1025 = 5 * 5* 41
625 = 5 *5 *5* 5

comparing the factors if a number appears twice just use it once an include all others
so the lcm is
5*5*5*5*41 = 25625