Factorize

1.
x²-12xy+36y²-x+6y
=(x-6y)^2+(x-6y)
=(x-6y)(x-6y+1)
2
1-x²+4xy-4y²

=1-(x-2y)^2
=[1+(x-2y)][1-(x-2y)]
=(1+x-2y)(1-x+2y)
3
x^6+2x^4y²+y^4x²-4
=(x^3+xy^2)^2-2^2
=(x^3+xy^2+2)(x^3+xy^2-2)



2007-01-26 01:37:19 補充：
重要公式a^2-b^2=(a+b)(a-b)

2007-01-26 02:38:16 補充：
oh, sorry﹐做錯了you are rightx²-12xy+36y²-x+6y=(x-6y)^2-(x-6y)=(x-6y)(x-6y-1)萬分致歉