i make a question myself. as follows.
2xy+2yz+2xz+x22+y2+z2
=?
=?
....
請列式。
factorize
2007-01-27 8:33 pm
回答 (2)
2007-01-27 10:20 pm
✔ 最佳答案
I just suggest another method here, but the solution of y99shto is fine.2xy + 2yz + 2xz + x^2 + y^2 + z^2
= x^2 + 2xy + y^2 + 2xz + 2yz + z^2
= (x + y)^2 + 2(x + y)z + z^2
= [(x + y) + z]^2
= (x + y + z)^2
2007-01-29 2:34 am
2xy+2yz+2xz+x2+y2+z2
=x2+2xy+y2+2yz+2xz+z2
=(x+y)2+z(x+y)+z2+xy+yz
=(x+y)(x+y+z)+z2+xy+yz
=(x+y)(x+y+z)+z(x+y+z)
=(x+y+z)(x+y+z)
=(x+y+z)2
=x2+2xy+y2+2yz+2xz+z2
=(x+y)2+z(x+y)+z2+xy+yz
=(x+y)(x+y+z)+z2+xy+yz
=(x+y)(x+y+z)+z(x+y+z)
=(x+y+z)(x+y+z)
=(x+y+z)2
收錄日期: 2021-04-12 23:25:17
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20070127000051KK01429