Newton's law of universal gravitation states that the force of gravity between two objects is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. Mathematically, it is expressed as:

F = G * (m1 * m2) / r^2

Where:

• F is the gravitational force between two objects.
• G is the gravitational constant.
• m1 and m2 are the masses of the two objects.
• r is the distance between the centers of the two objects.

The value of the gravitational constant is approximately 6.674 × 10^-11 N·m^2/kg^2 in the International System of Units (SI units).