An astronomical unit (AU) is the average distance between Earth and the sun. One AU is equal to approximately 150,000,000 km. Astronomers also use light years to measure distance. A light year is approximately 9.5×1012 km.

Answer 1

and ... ??
Maybe you want 1 light year =
(9.5*10^12)/(1.5*10^8) km

Answer 2

I mean AU, not km