Use a special product pattern to find the product $( 7 x + 2 ) ( 7 x - 2 )$ .
A) $49 x ^ { 2 } - 4$
B) $49 x ^ { 2 } - 28 x + 4$
C) $49 x ^ { 2 } + 4$
D) $49 x ^ { 2 } - 9 x - 4$
E) $49 x ^ { 2 } - 14 x + 4$

Question

Quizplus · Accepted Answer

This is a special product pattern known as the difference of squares: $(a+b)(a-b) = a^2 - b^2$. In this case, $a = 7x$ and $b = 2$, so we have $(7x+2)(7x-2) = (7x)^2 - (2)^2 = 49x^2 - 4$. Therefore, the best choice is A.

Use a Special Product Pattern to Find the Product (7x+2)(7x−2)( 7 x + 2 ) ( 7 x - 2 )(7x+2)(7x−2)

Use a Special Product Pattern to Find the Product $( 7 x + 2 ) ( 7 x - 2 )$