1)x^3-4x^2-21x
问题描述:
1)x^3-4x^2-21x
2)x^2y+10xy+25y
答
1)x^3-4x^2-21x
=x(x^2-4x-21)
=x(x+3)(x-7)
2)x^2y+10xy+25y
=y(x^2+10x+25)
=y(x+5)^2