Question

$9x^2-4y^2$ can be written as :

• A. $(3x+2y)(3x-2y)$
• B. $(3x+2y{)}^2$
• C. $(3x-2y{)}^2$
• D. $(9x-2y)\left(2y\right)$

Answer 1

The correct option is A $(3x+2y)(3x-2y)$

We know,
$a^2-b^2=(a+b)(a-b)$

$\therefore$
$9x^2-4y^2=(3x{)}^2-(2y{)}^2$
$\Rightarrow$ $(3x{)}^2-(2y{)}^2=(3x+2y)(3x-2y)$