1) a^2+6a+9=? 呢d題我唔係好識6a應該點做..
6a對條題目有咩影響..係咪唔使理?
2) 81-(2x-3y)^2=?
3) (2x-y)^2-x^2=?
ｔｈｚ！步驟．
更新1:
請加以解釋！
更新2:
＾２＝２次方
數學(簡單) １０！
2007-08-14 9:26 pm
分解為因式：
1) a^2+6a+9=? 呢d題我唔係好識6a應該點做..
6a對條題目有咩影響..係咪唔使理?
2) 81-(2x-3y)^2=?
3) (2x-y)^2-x^2=?
ｔｈｚ！步驟．
1) a^2+6a+9=? 呢d題我唔係好識6a應該點做..
6a對條題目有咩影響..係咪唔使理?
2) 81-(2x-3y)^2=?
3) (2x-y)^2-x^2=?
ｔｈｚ！步驟．
回答 (2)
2007-08-14 9:45 pm
✔ 最佳答案
1) a^2+6a+9 = ?a^2+6a = -9
a(^2+6) = -9
a = -9/(^2+6)
2) 81-(2x-3y)^2 = ?
(2x-3y)^2 = 81
2x-3y = 81/^2
3) (2x-y)^2-x^2 = ?
(2x-y)^2 = x^2
2x-y = x^2/^2
2x-y = x
2x-x = y
1x = y
其實，呢d係咩數呀......究竟係每條要求咩代數都唔講清楚...
我都唔明有咩簡單...
我盡量俾d step你...
仲有想問...^..這個符號係咪要跟住前面果個家...
可以既話就補充下啦...good luck!
參考: 自己諗
2007-08-14 9:55 pm
6a coeficient is 6.
6/2=3
so 1) (a+3)^2
6a can be used to determine the base of the final answer.
2) (9+2x-3y)(9-2x+3y)
3) (2x-y+x)(2x-y-x)
=(3x-y)(x-y)
OR
(2x-y)^2-x^2
=4x^2-4xy+y^2-x^2
=3x^2-4xy+y^2
=(3x-y)(x-y)
(The first method should be better.)
6/2=3
so 1) (a+3)^2
6a can be used to determine the base of the final answer.
2) (9+2x-3y)(9-2x+3y)
3) (2x-y+x)(2x-y-x)
=(3x-y)(x-y)
OR
(2x-y)^2-x^2
=4x^2-4xy+y^2-x^2
=3x^2-4xy+y^2
=(3x-y)(x-y)
(The first method should be better.)
參考: my brain
收錄日期: 2021-04-18 22:58:31
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