How do you factor completely $a^2 - 121b^2$ ?

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Answer 1 · 2015-11-14T04:13:16

$color(blue)((a+11b)(a-11b)$

$a^2−121b^2$
This expression can be rewritten as $(a)^2−(11b)^2$

Now, as per the below property,
$color(blue)(x^2-y^2=(x+y)(x-y)$ , we can rewrite the expression as:

$(a)^2−(11b)^2=color(blue)((a+11b)(a-11b)$
(Here, $x=a,y=11b$ )

So the factorised form of the expression is:
$=color(blue)((a+11b)(a-11b)$

How do you factor completely a^2 - 121b^2a^2 - 121b^2?