a) 4x2 – 6x3y – 2x2 + 8x = 2x ( 2x - 3 x\(^2\)y - x + 4 )
b) x2 – 4 – 2xy + y2 = ( x2– 2xy + y2) \(-4\) = ( x - y )\(^2\) - 2\(^2\)
= ( x - y - 2 ) ( x - y + 2 )
c) x3 – 4x2 – 12x +27
= (x\(^3\) + 27 ) - ( 4x\(^2\) + 12x )
= ( x + 3 ) ( x\(^2\) - 3x + 9 ) - 4x ( x + 3)
= ( x + 3 ) ( x\(^2\) - 3x + 9 - 4x )
= ( x + 3 ) ( x\(^2\) - 7x + 9 )
d) 3x2 – 18x + 27 = 3 ( x\(^2\) - 6x + 9 )