(9 cdot 10^9 cdot 1 cdot 10^-8 cdot 2 cdot 10^-9)/((3 cdot 10^-3))^(2)-(9 cdot 10^9 cdot 1,6 cdot 10^-8 cdot 2 cdot 10^-9)/((4 cdot 10^-3))^(2)

To solve the given expression, let's break it down step by step: First, let's simplify the numerator and denominator of each fraction separately.For the first fraction: For the denominator: So, the first fraction becomes: For the second fraction: For the denominator: So, the second fraction becomes: Now, let's subtract the second fraction from the first fraction: Since is a very small number, it can be approximated as 0 for practical purposes. Therefore, the final answer is: So, the correct answer is .