Answer:

Step-by-step explanation:
Two casess are mentioned in the given figure
first case
two mass m and M_1
m is l_1 distance from center and M_1 is l_2 distance from center
second case
two mass m and M_2
m is l_2 distance from center and M_2 is l_1 distance from center
The balance in the 1st case requires

And the balance in second case
Cancel

from the above equations.
So
, i.e.
