Question

The distance between Earth and Mars is 225 million km. When converted using the conversion factor 1 AU = 1.5 × 108 km, the distance between the planets is . The astronomical unit (AU) is a light-year.

Answer 1

I guess the problem is asking for the distance between Earth and Mars in Astronomical Units (AU).

Since $1 AU = 1.5 \cdot 10^8 km$
and the distance between the two planets is
$d=225 mil. km= 2.25 \cdot 10^8 km$
we can convert this distance into AU by using the following proportion:
$1 AU : 1.5 \cdot 10^8 km = x : 2.25 \cdot 10^8 km$

from which we find
$x= \frac{1 AU \cdot 2.25 \cdot 10^8 km}{1.5 \cdot 10^8 km} =1.5 AU$

Answer 2

AU = 1.5 × 108  yes that is correct.