The expression \( 4x^2 - 81y^2 \) is a difference of squares. The difference of squares formula is:
\[
a^2 - b^2 = (a + b)(a - b)
\]
Here, \( a = 2x \) and \( b = 9y \), since \( (2x)^2 = 4x^2 \) and \( (9y)^2 = 81y^2 \).
Applying the formula, we get:
\[
4x^2 - 81y^2 = (2x)^2 - (9y)^2 = (2x + 9y)(2x - 9y)
\]
So, the correct factorization is:
\[
(2x + 9y)(2x - 9y)
\]
Thus, the correct choice is:
\[
(2x + 9y)(2x – 9y)
\]
10.
Factor the expression.
4x2 – 81y2
(2x + 9y)2
(2x – 9y)2
(2x + 9y)(2x – 9y)
(2x + 9)(2x – 9)
1 answer