Explanation:
Recession velocity of a galaxy is related to the distance at which the galaxy is located. This relationship is given by the hubble constant, as follows:
[tex]v_r=HD[/tex]
Hubble constant is aproximate [tex]70\frac{km/s}{Mpc}[/tex] and 1 megaparsec (Mpc) is 3.26*10^6 light years. Rewriting for D:
[tex]D=\frac{v_r}{H}[/tex]
For galaxy A:
[tex]D=\frac{2000\frac{km}{s}}{70\frac{km/s}{Mpc}}\\\\D=28.57Mpc\\\\D=28.57Mpc*\frac{3.26*10^6ly}{1Mpc}=9.31*10^7ly[/tex]
For galaxy B:
[tex]D=\frac{6000\frac{km}{s}}{70\frac{km/s}{Mpc}}\\\\D=85.71Mpc\\\\D=85.71Mpc*\frac{3.26*10^6ly}{1Mpc}=2.79*10^8ly[/tex]
