According to the Negative exponent rule, you know that:
[tex]b^{-n}=\frac{1}{b^n}[/tex]According to the Product of powers property, you have that:
[tex]b^n\cdot b^m=b^{(n+m)}[/tex]Equivalent expressions have the same value, but they are written in different forms. For this case, you have this expression:
[tex]10^3\cdot10^{-5}\cdot2^{-8}[/tex]Simplify it in order to find an equivalent expression. Applying the Product of powers property:
[tex]=10^{3+(-5)}\cdot2^{-8}=10^{-2}\cdot2^{-8}[/tex]Finally, applying the Negative exponent rule, you get this equivalent expression with only positive exponents:
[tex]=\frac{1}{10^2\cdot2^8}[/tex]The answer is Option 2.