爆急f.2 factorize!!!!!!!!!!!!!!!!!聽日交!!

弊傢伙!
全部錯哂喎!
咁大整蠱!

(2p+q)(x+y) - px - py
=(2p+q)(x+y) -p(x+y)
=(x+y)(2p+q-p)
=(x+y)(p+q)

x² - y² - 2y - 1
=(x+y)(x-y)-(2y+1)

2008-04-01 13:41:44 補充：
I am sorry,
x² - y² - 2y - 1
=x² - (y² +2y + 1)
=x² - (y+ 1)²
=(x+y-1)(x-y+1)

(2p+q)(x+y) - px - py
=2px+2py+qx+qy-px-py
=px+py+qx+qy
=(p+q)(x+y)

x² - y² - 2y - 1
=x²-y²-2y-1+xy-xy+x-x
=x²-y²-y-y-1+xy-xy+x-x
=x²+xy-x -xy-y²-y +x-y-1
=(x+y+1)(x-y-1)

(2p+q)(x+y)-px-py
=(2p+q)(x+y)-p(x+y)
=(2p+q-p)(x+y)
=(p+q)(x+y)

(2p+q)(x+y) - px - py
=(2p+q)(x+y)-p(x+y)
=(2p+q-p)(x+y)
=(p+q)(x+y)
x - y - 2y - 1
=x2-(y2+2y+1)
=x2-(y+1)2
=(x-y+1(x+y+1)

= 2px + 2py + qx+ qy
=(2p+q)x+(2p+q)y
=(x+y)(2p+q)