求數學1元3次式方程
回答 (2)
2010-10-04 8:02 pm
✔ 最佳答案
2x^3－3x^2－17x+30=0，求xSol
2x^3－3x^2－17x+30=0
2x^3+6x^2－9x^2－27x+10x+30=0
2x^2(x+3)－9x(x+3)+10(x+3)=0
(2x^2－9x+10)(x+3)=0
(2x－5)(x－2)(x+3)=0
x=5/2or x=2 or x=－3
2010-10-06 5:11 am
3x^2－17x+30=0
2x^3+6x^2－9x^2－27x+10x+30=0
2x^2(x+3)－9x(x+3)+10(x+3)=0
(2x^2－9x+10)(x+3)=0
(2x－5)(x－2)(x+3)=0
x=5/2or 2 or －3
2x^3+6x^2－9x^2－27x+10x+30=0
2x^2(x+3)－9x(x+3)+10(x+3)=0
(2x^2－9x+10)(x+3)=0
(2x－5)(x－2)(x+3)=0
x=5/2or 2 or －3
收錄日期: 2021-04-23 19:23:23
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