# How do you factor 16-4a^2 ?

May 17, 2015

property :
color(blue)(a^2 - b^2 = (a+b)(a-b)

expression given is:
$16 - 4 {a}^{2}$
$= {4}^{2} - {\left(2 a\right)}^{2}$
here , $a = 4 \mathmr{and} b = 2 a$

rewriting the expression:
${4}^{2} - {\left(2 a\right)}^{2} = \left(4 + 2 a\right) \left(4 - 2 a\right)$ , this is the factorised form.