Final answer:
Hubble's Law equation, v = H x d, allows calculation of galaxy distances by relating their radial velocities due to redshift to their distances from us, using Hubble's constant as a proportionality factor.
Step-by-step explanation:
Hubble's Law relates radial velocities of remote galaxies to their distances from us, providing a method to determine the distance to remote galaxies. This law, represented as v = H x d, where v is the radial velocity of a galaxy moving away from Earth, H is Hubble's constant, and d is the distance to the galaxy, helps astronomers calculate how far away a galaxy is based on its observed redshift. The redshift occurs due to the expansion of the universe, which stretches the light from galaxies, causing spectral lines to appear shifted toward the red end of the spectrum. Hubble's constant is crucial in this calculation and has been measured through extensive observation to be about 22 km/s per million light-years.