I want a clear solution an explanation of how to solve this, please.

Step-by-step explanation:

In this problem, we are expected to perform a subtraction operation on two numbers and leave the answer in scientific notation.

6.24x10^12 and 4.89×10^10

6.24x10^12 -4.89×10^10

Let us make the number on the left to have the same indices as the one on the right.

624x10^10-4.89x10^10

We can now subtract the numbers since they have similar indices

(624-4.89)x10^10

619x10^10