解4x* + 6x - 5(√2x* + 3x + 9) + 15 = 0
* 為次方
√為開方
4x* + 6x - 5(√2x* + 3x + 9) + 15 = 0
4x* + 6x +18 - 18 - 5(√2x* + 3x + 9) + 15 = 0
2(2x* + 3x + 9) - 5(√2x* + 3x + 9) + 15 - 18 = 0
2(2x* + 3x + 9) - 5(√2x* + 3x + 9) + 3 = 0
我做到呢度做唔到落去
而下一步係要轉為
〔2(√2x* + 3x + 9) + 1〕．〔(√2x* + 3x + 9) - 3〕= 0
我唔識點轉到呢一步
而答案係 x = 0 or x = - 3分之2
MATHS QUESTION
2008-08-16 12:38 am
回答 (2)
2008-08-16 1:32 am
✔ 最佳答案
運算上的錯誤: 15 - 18 = -3 不是3!圖片參考：http://i238.photobucket.com/albums/ff245/chocolate328154/Maths389.jpg?t=1218792699
2008-08-16 01:19:50 補充：
請按reload看解釋。
參考: My Maths Knowledge
2008-08-16 12:59 am
Put x = 0 into 4x² + 6x - 5(√2x² + 3x + 9) + 15 = 0
L.H.S = 0+0-5(0+0+9)+15=-30
R.H.S=0
................................................................................= ="
L.H.S = 0+0-5(0+0+9)+15=-30
R.H.S=0
................................................................................= ="
收錄日期: 2021-04-13 15:57:47
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