1. ## [SOLVED] basic factoring problems

factor completely

$(c-d)^2-e^2$
$m^2-(n-1)^2$
$x^4-1$

wow i am so stupid i completely forgot $a^2-b^2$

2. you just need to know that

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

for example last one

$x^4 -1 = (x^2 -1 )( x^2 +1 ) = (x-1)(x+1)(x^2+1)$