Question

因式分解分组法

1.ab-a+b-1
2.3m+nx-3n-mx
3.xy-xz-y方-2yz-z方

Answer 1

1.
ab-a+b-1
=(ab-a)+(b-1)
=a(b-1)+(b-1)
=(a+1)(b-1)

2.
3m+nx-3n-mx
=(3m-3n)-(mx-nx)
=3(m-n)-x(m-n)
=(3-x)(m-n)

3.
题目有误，
xy-xz-y^2+2yz-z^2
=(xy-xz)-(y^2-2yz+z^2)
=x(y-z)-(y-z)^2
=(y-z)(x-y+z)

Answer 2

1.a(b-1)+b-1
=(a+1)(b-1)

2.3(m-n)+x(n-m)
=(3-x)(m-n)

3.x(y-z)-(y-z)^2
=(x-y+z)(y-z)