Question

Factorise $x^2-16$

• A. $(x+2)(x-2)$
• B. $(x+4)(x-4)$
• C. $(x+4)(x+5)$
• D. $16-x^2$

Answer 1

The correct option is B $(x+4)(x-4)$

$x^2-16$
We know $a^2-b^2=(a+b)(a-b)$
$a=xandb=4$
$x^2-4^2=(x-4)(x+4)$