The correct option is C (y2+2y−4)(y4−2y3+8y2+8y+16)
y6+32y3−64
=y6+8y3−64+24y3
=(y2)3+(2y)3−43−3(y2)(2y)(−4)
Using, a3+b3+c3−3abc=(a+b+c)(a2+b2+c2−ab−ac−bc)
=(y2+2y−4)((y2)2+(2y)2+(−4)2−(y2)(2y)−(y2)(−4)−(2y)(−4))
=(y2+2y−4)(y4+4y2+16−2y3+4y2+8y)
=(y2+2y−4)(y4+8y2+16−2y3+8y)