Answer:
7 * 10^8
Step-by-step explanation:
(9.6 * 10^9) - (8.9 * 10^9) =
= (10^9) * (9.6 - 8.9)
= (10^9) * 0.7
= 0.7 * 10^9
= 7 * 10^-1 * 10^9
= 7 * 10^8
