Which of the following formulas represents Newton's second law?

Newton's second law of motion is fundamentally expressed as the relationship between the force applied to an object, its mass, and its acceleration. The correct formula, which states that force is equal to mass multiplied by acceleration, illustrates how the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass.

When the net force increases while mass remains constant, the acceleration of the object increases. Conversely, if the mass increases and the net force stays the same, the acceleration decreases. This relationship is pivotal in understanding how objects move and respond to forces.

The other formulas do not accurately reflect this fundamental principle. For instance, adding or subtracting mass and acceleration does not represent any physical relationship related to motion, nor does dividing mass by acceleration provide a meaningful concept in the context of Newton's laws. Hence, the chosen formula encapsulates the essence of how forces affect the motion of objects.