ANSWER
[tex]10^6[/tex]EXPLANATION
We want to simplify the fraction below:
[tex]\frac{10^9}{10^3}[/tex]When you have a fraction of powers and the numerator and denominator have the same base (e.g. 10 in this case), the power on the denominator is subtracted from the power of the numerator.
So, that is:
[tex]\begin{gathered} 10^{9-\text{ 3}} \\ =>10^6 \end{gathered}[/tex]That is the answer.