Hi! Newton's law of universal gravitation states that each and every particle in the universe attracts every other particle in the universe with a force which is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers.

In mathematical terms,

Let F be force.

Then F is directly proportional to M1 and M2, where M1 and M2 are the respective masses of the two bodies.

Also, F is inversely proportional to r^2 ( where r is the distance between the the two masses)

Then F= G*M1*M2/(r^2)

Here, G is the constant of proportionality, the Gravtiation Constant. Hope this helps!