What is the product?

[tex]\[ (9t - 4)(-9t - 4) \][/tex]

A. [tex]\(-81t^2 - 16\)[/tex]

B. [tex]\(-81t^2 + 16\)[/tex]

C. [tex]\(-81t^2 - 72t + 16\)[/tex]

D. [tex]\(-81t^2 + 72t + 16\)[/tex]



Answer :

Let's determine the product of the given expressions step by step:

Given expressions:
[tex]\[ (9t - 4)(-9t - 4) \][/tex]

We'll use the distributive property, also known as the FOIL method (First, Outer, Inner, Last), to expand this expression.

1. First terms: Multiply the first terms in each expression.
[tex]\[ 9t \cdot (-9t) = -81t^2 \][/tex]

2. Outer terms: Multiply the outer terms in the expression.
[tex]\[ 9t \cdot (-4) = -36t \][/tex]

3. Inner terms: Multiply the inner terms.
[tex]\[ -4 \cdot (-9t) = 36t \][/tex]

4. Last terms: Multiply the last terms in each expression.
[tex]\[ -4 \cdot (-4) = 16 \][/tex]

Now, we sum up all these terms:
[tex]\[ -81t^2 + (-36t) + 36t + 16 \][/tex]

Combine the like terms ([tex]\(-36t + 36t\)[/tex]):
[tex]\[ -81t^2 + 0t + 16 \][/tex]

We can simplify this to:
[tex]\[ -81t^2 + 16 \][/tex]

Therefore, the correct answer is:
[tex]\[ -81t^2 + 16 \][/tex]

So, the correct choice from the given options is:
[tex]\[ -81t^2 + 16 \][/tex]