The equation that shows how velocity (v), frequency (f), and wavelength (λ) are related is:

v = fλ

This equation is applicable for all waves, including sound waves and electromagnetic waves (like light).

Here's what each variable represents:

* v: Velocity of the wave (usually measured in meters per second, m/s)

* f: Frequency of the wave (usually measured in Hertz, Hz, which is cycles per second)

* λ: Wavelength of the wave (usually measured in meters, m)

This equation essentially states that the velocity of a wave is directly proportional to both its frequency and wavelength. This means that if you increase the frequency or the wavelength, the velocity of the wave will also increase.