Use a special product pattern to find the product $( x + 9 ) ( x - 9 )$ .
A) $x ^ { 2 } - 18 x + 81$
B) $x ^ { 2 } - 81$
C) $x ^ { 2 } + 81$
D) $x ^ { 2 } + 18 x + 81$
E) $x ^ { 2 } - 18$

Question

Quizplus · Accepted Answer

This problem can be solved using the formula $(a+b)(a-b) = a^2 - b^2$. If we let $a=x$ and $b=9$, we get:
$$(x+9)(x-9) = x^2 - 9^2 = x^2 - 81$$
Therefore, the correct answer is B.

Use a Special Product Pattern to Find the Product (x+9)(x−9)( x + 9 ) ( x - 9 )(x+9)(x−9)

Use a Special Product Pattern to Find the Product $( x + 9 ) ( x - 9 )$