Question

(y^2-1)(y+3)(y+5)+15分解因式

详细过程谢谢大家

Answer 1

原式=(y+1)(y-1)(y+3)9y+5)+15
=[(y-1)(y+5)][(y+1)(y+3)]+15
=[(y²+4y)-5][(y²+4y)+3]+15
=(y²+4y)²-2(y²+4y)-15+15
=(y²+4y)²-2(y²+4y)
=(y²+4y)(y²+4y-2)
=y(y+4)(y²+4y-2)

Answer 2

(y^2-1)(y+3)(y+5)+15
=(y-1)(y+1)(y+3)(y+5)+15
=[(y-1)(y+5)][(y+1)(y+3)]+15
=(y^2+4y-5)(y^2+4y+3)+15
=(y^2+4y)^2-2(y^2+4y)
=(y^2+4y)(y^2+4y-2)
=y(y+4)(y^2+4y-2)