Question 237840
Steps:
a. need to convert one of the units to the other in order to add them up
b. since your problem doesn't specify which unit to express the result, I'll convert km into miles.
b. add the miles 
c. express answer in scientific notation
.
Problem:
Since 1 km = 0.62 miles...
57,910,000 km *0.62 mi / 1km ...km units cancel...
35,904,200 miles
Now add it to the other distance
35,904,000+93,000,000
128,904,200 miles
Now in scientific notation:
1,289*10^5 miles