what is the product? (9t - 4)(-9t - 4) -81t² - 16 -81t² + 16 -81t² - 72t + 16 -81t² + 72t + 16

Explanation:

Step1: Use the difference - of - squares formula

We know that $(a - b)(a + b)=a^{2}-b^{2}$. Here, $a=-4$ and $b = 9t$. So, $(9t - 4)(-9t - 4)=(-4 + 9t)(-4-9t)$.

Step2: Apply the formula

According to the formula $(a + b)(a - b)=a^{2}-b^{2}$, we have $(-4)^{2}-(9t)^{2}$.

Step3: Calculate the squares

$(-4)^{2}=16$ and $(9t)^{2}=81t^{2}$. So, $(-4)^{2}-(9t)^{2}=16 - 81t^{2}=-81t^{2}+16$.

Answer:

-81t² + 16, which corresponds to the second option.