X² - (Y-Z)²
X² = (Y-Z)²
X = Y-Z
X - Y + Z =0
(我可吾可以咁做?)
2X (N+1) - 7X (N) - 15X (N-1)
(括號是次方)
MATHS LONG Q
2007-08-21 8:25 am
回答 (2)
2007-08-21 9:03 am
✔ 最佳答案
X² - (Y-Z)²=0X² = (Y-Z)² <===OK
X = Y-Z or -X=Y-Z <===== square root results in positive or negative
X - Y + Z =0 or X+Y-Z=0
You may use:
[x-(Y-Z)][x+(Y-Z)]=0
X - Y + Z =0 or X+Y-Z=0
2X (N+1) - 7X (N) - 15X (N-1)
[2X^2-7X-15]X^(N-1)
[(2X+3)(X-5)]X^(N-1)
參考: my knowledge
2007-08-21 6:23 pm
I think the correct answers are:
X^2 - (Y-Z)^2 [Applying a^2-b^2 = (a+b)(a-b)]
=[X+(Y-Z)][X-(Y-Z)]
=(X+Y-Z)(X-Y+Z)
2X^(N+1) - 7X^N - 15X^(N-1)
=X^(N-1) (2X^2 - 7X - 15)
=X^(N-1) (2X+3)(X-5)
X^2 - (Y-Z)^2 [Applying a^2-b^2 = (a+b)(a-b)]
=[X+(Y-Z)][X-(Y-Z)]
=(X+Y-Z)(X-Y+Z)
2X^(N+1) - 7X^N - 15X^(N-1)
=X^(N-1) (2X^2 - 7X - 15)
=X^(N-1) (2X+3)(X-5)
收錄日期: 2021-04-13 13:01:43
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20070821000051KK01047