The differential equation \( \frac{dy}{dx} + y = 5 \) is separable.
Solving: \[ \frac{dy}{dx} = 5 - y \] \[ \frac{1}{5 - y} dy = dx \] Integrating both sides gives \( -\log|5 - y| = x + C \).
Kepler's second law (law of areas) of planetary motion leads to law of conservation of