Solve the following quadratic equations
1. (2x - 5) = (x - 3) (2x - 5)
2. 3x - 8x + 4 = 0
F.4 maths questions
2008-10-06 8:37 am
回答 (2)
2008-10-06 10:38 am
✔ 最佳答案
(2x-5) = (x-3) (2x-5)2x-5=2x^2-11x+15
2x^2-13x+20=0
(2x-5)(x-4)=0
x=4 or x=2.5
3x - 8x + 4 = 0
-5x+4=0
-5x=-4
x=-4/-5
x=4/5(0.8)
2008-10-06 02:39:45 補充：
樓上第一題錯在將 2x-5 除 2x-5，排除了2x-5=0既可能性
2008-10-06 8:50 am
1.(2x-5) = (x-3) (2x-5)
(2x-5)/(2x-5)=(x-3)
1=x-3
x=-3
2. 3x - 8x + 4 = 0
-5x+4=0
-5x=-4
x=-4/-5
x=4/5(0.2)
(2x-5)/(2x-5)=(x-3)
1=x-3
x=-3
2. 3x - 8x + 4 = 0
-5x+4=0
-5x=-4
x=-4/-5
x=4/5(0.2)
參考: Me(我係f.3,唔知岩唔岩)
收錄日期: 2021-04-13 16:59:57
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https://hk.answers.yahoo.com/question/index?qid=20081006000051KK00067