1.x平方+6y-xy-6x
=x^2-xy-6x+6y
=x(x-y)-6(x-y)
=(x-6)(x-y)
2.a平方-a-b平方+b
=a^2-b^2-(a-b)
=(a+b)(a-b)-(a-b)
=(a+b-1)(a-b)
3.4x平方-y平方+2x+y
=(2x+y)(2x-y)+(2x+y)
=(2x-y+1)(2x+y)
4.x三次方-x平方-x+1
=x^3-x-(x^2-1)
=x(x^-1)-(x^2-1)
=(x-1)(x^2-1)
5.am-bm+an-bn
=(a-b)m+(a-b)n
=(a-b)(m-n)
6.x平方-xy+xz-yz
=x(x-y)+z(x-y)
=(x+z)(x-y)