Answer:
The distance is 55.636 billion miles, or 528.2 AU.
Step-by-step explanation:
Since the distance from the Sun to Neptune is 2.7818 billion miles, the distance from the Sun to Planet Nine would be 20 times that, which is:

or 55.636 billion miles.
Since 1 astronomical unit (AU) is 93 million miles, that distance is also:
