Question

What is the product? (9t − 4)(−9t − 4) −81t2 − 16 −81t2 + 16 −81t2 − 72t + 16 −81t2 + 72t + 16

Answer 1

Answer:

Option 2nd is correct

$-81t^2+16$

Step-by-step explanation:

To find the product of:

$(9t-4)(-9t-4)$

We can write this as:

$-(9t-4)(9t+4)$

Using identity rule:

$(a+b)(a-b) = a^2-b^2$

then;

$-((9t)^2-(4)^2)$

⇒$-(81t^2-16)$

Using distributive property i.e, $a \cdot (b+c) = a\cdot b+ a\cdot c$

$-81t^2+16$

Therefore, the following given product is, $-81t^2+16$

Answer 2

Answer:

$-81t^{2}+16$

Step-by-step explanation:

we have

$(9t - 4)(-9t - 4)$

Applying distributive property

$(9t - 4)(-9t - 4)=(9t*-9t)+(9t*(-4))+(-4*(-9t))+(-4*(-4))\\=-81t^{2} -36t+36t+16\\=-81t^{2}+16$