Answer:
Explanation:
I will take a to be 52.6 * 10^-9 The number should be 5.26 * 10^-8 so A is not the answer.
6.39*10^9 This one is correct.
0.12 * 10^-2 is not correct. It should be 1.2*10^-3
10 * 10 ^7 should be 1*10^8 so D is not correct.
The coefficient of scientific notation must be a number between 1 and 10 and including 1 but not 10. This is written as 1 ≤x <10