1 AU = it is defined as distance of Earth from Sun
it is also known as solar distance
So here we know that distance of Earth and Sun is
[tex]1 AU = 1.5 * 10^{11} meter[/tex]
1 Light Year = It is defined as the distance covered by light in 1 year of time
it is calculated by simple product of speed * time
[tex]1 Ly = c*t[/tex]
[tex]c = 3* 10^8 m/s[/tex] = speed of light
[tex]t = 1 year = 365 * 24 * 3600 s[/tex]
[tex]t = 3.15 * 10^7 s[/tex]
now we can find the value of 1 Ly
[tex]1 Ly = 9.46 * 10^{15} m[/tex]
now Voyager distance is given as
[tex]d = 141 AU[/tex]
now in order to convert it into Ly we can say
[tex]d = 141 * 1.5 * 10^{11} = 2.115 * 10^{13} m[/tex]
now we have
[tex]d = \frac{2.115 * 10^{13}}{9.46 * 10^{15}}[/tex]
[tex]d = 2.24 * 10^{-3} Ly[/tex]
so the distance in light year must be 0.00224 Light years