Difference of squares: a2 - b2 =(a + b)(a - b)

Go !

Calculate and simplify:

$\LARGE (axy-1)(1+axy) =$	$\LARGE a^2x^2y^2-1$
$\LARGE (a^2-b^3)(a^2+b^3) =$	$\LARGE a^4-b^6$
$\LARGE (xy+3)(xy-3)(\frac{x^2y^2+9}{2}) =$	$\LARGE \frac{x^4y^4-81}{2}$

Factorize:

$\LARGE x^6-y^2 =$	$\LARGE (x^3+y)(x^3-y) $
$\LARGE a^3-ab^2 =$	$\LARGE a(a+b)(a-b)$
$\LARGE - (x^2+1)^2 + 1 =$	$\LARGE - x^2(2 + x^2)$