a. a^3 – a^2x – ay + xy b. xy(x + y) + yz(y + z) + xz(x + z) + 2xyz

a) a³−a²x−ay+xy

=a²(a−x)−y(a−x)

=(a²−y)(a−x)

b) xy(x+y)+yz(y+z)+xz(x+z)+2xyz

= xy(x + y) + yz(y + z) + xyz + xz(x + z) + xyz

= xy(x + y) + yz(y + z + x) + xz(x + z + y)

= xy(x + y) + z(x + y + z)(y + x)

= (x + y)(xy + zx + zy + z²)

= (x + y)[x(y + z) + z(y + z)]

= (x + y)(y + z)(z + x)

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