After that prelude, the question is this:Let and be positive rational numbers. We define the lowest common multiple of and , lcm , to be the smallest positive rational number q such that for some positive integers M and N.

I know that but I have no idea where to go from here.Find a formula for . Your answer can include expressions of the form lcm(m,n) and hcf(m,n) where m and n are integers.

Can someone point me in the right direction?