factorize

factorize:(form 3)
1)
3(x+7)^2+(x+7)(x-6)-14(x-6)^2
= [3(x+7) + 7(x-6)] * [(x+7) -2*(x-6)]
=[3x+21 + 7x-42] * [x+7 -2x +12]
=(10x-21)*(-x+19)
2) Question is modified!
(x+2)^2-(x+2)(y-3)-6(y-3)^2
=[(x+2)-3*(y-3)]*[(x+2)+2(y-3)]
=(x -3y-7) * (x+2y-4)




2006-12-05 18:49:13 補充：
Question 2 answer should be:=(x -3y 11) * (x 2y-4)

2006-12-07 12:09:47 補充：
=(x-3y+11) * (x+2y-4)