What is real law of gravitation of newton in his own words?

Answer 1

Newton's Law of Universal Gravitation was first published in 1687 as part of his book,

Philosophiæ Naturalis Principia Mathematica. The publication is free of copyright, and may be viewed online.

Newton did not originate the concept of gravity, but was the first to demonstrate that the motion of the celestial bodies could be explained if they were acting under an attractive force which was inversely proportional to the squares of the distances between them, and proportional to their masses. The gravitational constant was not determined until two centuries later. Newton did not promote the invisible force of gravity in his work, or attempt to explain it. The book solves the equation of motion for several types of orbits acting under several different forms of radial forces, and explains several astronomical observations with an inverse square form.

The actual statements are similar to this one, "if bodies move uniformly in concentric circular orbits whose periods vary as the 3/2 power of the radii, then the centripetal forces acting on these bodies vary as the inverse-square of the radii of the orbits."