EXPLANATION
Since we have 900,000 kilometers, and 1 kilometer is equivalent to 0.621371 kilometers, we can apply the unitary method in order to get the needed conversion as shown as follows:
[tex]\text{?miles}=900,000\operatorname{km}\cdot\frac{0.621371}{1\text{kilometer}}=559233\text{ miles}[/tex]?miles = 900,000 km * (0.621371/ 1 km) = 559,233 miles
The solution is 559,233 miles
