Answer:
Step-by-step explanation:
[tex]\dfrac{4\cdot10^5}{5\cdot10^2}=\dfrac{4}{5}\cdot\dfrac{10^5}{10^2}=0.8\cdot10^{5-2}=0.8\cdot10^3=0.8\cdot1,000=800\\\\\\\text{Used}\ \dfrac{a^m}{a^n}=a^{m-n}[/tex]