Answer:
4.32 × 10^5
Explanation:
First, multiply 4.9 by 10^5=490000 and 5.8 by 10^4=58000. Subtract 58000 from 490000=432000. Then, scientific notation is a number between 1 and 10 being multiplied by a power of ten, so get 432000 down to a number between 1 and 10, which is 4.32 and 4.32 multiplied by 10^5 is 432000.
(hope this helps :P)