Determine the lowest common multiple LCM of the following three terms 3st,4s^2,5t^2

Answer 1

Take the highest power of any primes or variables.
So, 3*4*5 = 60 is one part of the LCM.
What about s and t?

Answer 2

3st,4s^2,5t^2

3st=3.s.t
4s^2=4.s.s
5t^2=5.t.t

Drop repeating s and t

Now LCD is 3.4.5.s.s.t.t
60s^2t^2