Factoriser

Got it ! Factoriser:

$4x^2 - (4x - 3y)^2 =$	$3(2x - y)(3y - 2x) $
$(b - 4)^2 - 9(b - 5)^2 =$	$(-2b+11)(4b -19) $
$ - 6(x^2 - 9) + (2x - 1)(x + 3) =$	$(x+3)(-4x+17) $
$x^2+2x+1-(x+1)(x-5) =$	$6(x+1) $
$8x^2+24x+18-2(y-2)^2 =$	$2(2x+y-5)(2x-y-1) $
$(a+1)^4-1 =$	$ a(a^2+2a+2)(a+2)$
$(a+1)-(1+a)^3 =$	$-a(a+1(a+2)) $
$a^2+4ab+3b^2 =$	$a^2+4ab+4b^2-b^2=(a+2b)^2-b^2=(a+3b(a+b)) $