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 :

Certainly! Let's find the product of the given expressions [tex]\( (9t - 4) \)[/tex] and [tex]\( (-9t - 4) \)[/tex].

First, let's write down the expressions:
[tex]\[ (9t - 4)(-9t - 4) \][/tex]

To find the product, we use the distributive property (also known as the FOIL method for binomials):
[tex]\[ (9t - 4)(-9t - 4) = (9t)(-9t) + (9t)(-4) + (-4)(-9t) + (-4)(-4) \][/tex]

Now, let's calculate each term individually:

1. The product of the first terms:
[tex]\[ (9t)(-9t) = -81t^2 \][/tex]

2. The product of the outer terms:
[tex]\[ (9t)(-4) = -36t \][/tex]

3. The product of the inner terms:
[tex]\[ (-4)(-9t) = 36t \][/tex]

4. The product of the last terms:
[tex]\[ (-4)(-4) = 16 \][/tex]

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

Notice that the [tex]\( -36t \)[/tex] and [tex]\( 36t \)[/tex] terms cancel each other out:
[tex]\[ -81t^2 + 0t + 16 \][/tex]

So, the expression simplifies to:
[tex]\[ -81t^2 + 16 \][/tex]

Therefore, the product of [tex]\( (9t - 4)(-9t - 4) \)[/tex] is:
[tex]\[ 16 - 81t^2 \][/tex]

Thus, the correct answer is:
[tex]\[ \boxed{16 - 81t^2} \][/tex]