Question

Which of the following identity can be used to factorize $x^2-4y^2$?

• A. $(a-b{)}^2=a^2-2ab+b^2$
• B. $a^2-b^2=(a-b)(a+b)$
• C. $(x+a)(x+b)=x^2+(a+b)x+ab$
• D. $(a-b{)}^2=a^2-2ab+b^2$

Answer 1

The correct option is B

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

$x^2-4y^2$ is in the form of $a^2-b^2$, where $a$ is $x$ and $b$ is $2y.$
So, $a^2-b^2=(a-b)(a+b)$ can be used.