Question

因式分解（要有过程)

-10x^2z+25xyz-15y^2z
x^2+(k+2)x+(k+1)
(x^2+3x)^2-8(x^2+3x)-20
4a^2 b^2-(a^2+b^2)^2

Answer 1

10x^2z+25xyz-15y^2z=5z(2x²+5xy-3y²)=5z((2x-y)(x+3y)

x^2+(k+2)x+(k+1)=(x+k+1)(x+1)

(x^2+3x)^2-8(x^2+3x)-20=(x²+3x+2)(x²+3x-10)=(x+1)(x+2)(x+5)(x-3)

4a^2 b^2-(a^2+b^2)^2=(2ab-a²-b²)(2ab+a²+b²)=-(a-b)²(a+b)²

追问

第一题你做了吧！题目是-10x^2z+25xyz-15y^2z

追答

-10x^2z+25xyz-15y^2z=-5z(2x²-5xy+3y²)=-5z(2x-3y)(x-y)