1. (2x -1)(x -2) = 5
2. (3x +5)(x -6) = (x -1)^2
MATHS......
2007-09-05 3:11 am
回答 (2)
2007-09-05 3:17 am
✔ 最佳答案
(2x -1)(x -2) = 5 2x^2-4x-x+2=5
2x^2-5x-3=0
(2x+1)(x-3)=0
x=1/2 or x=3//
(3x +5)(x -6) = (x -1)^2
3x^2-18x+5x-30=x^2-2x+1
2x^2-11x-31=0
x=7.55 or -2.05//
2007-09-05 3:21 am
1.
(2x-1)(x-2)=5
2x^2-x-4x+2=5
2x^2-5x-3=0
(x-3)(2x+1)=0
x-3=0 or 2x+1=0
x=3 or x=-1/2
2.
(3x+5)(x-6)=(x-1)^2
3x^2+5x-18x-30=x^2-2x+1
2x^2-11x-31=0
x=7.55 or x=-2.05(corr. to 3 sig. fig.)
(2x-1)(x-2)=5
2x^2-x-4x+2=5
2x^2-5x-3=0
(x-3)(2x+1)=0
x-3=0 or 2x+1=0
x=3 or x=-1/2
2.
(3x+5)(x-6)=(x-1)^2
3x^2+5x-18x-30=x^2-2x+1
2x^2-11x-31=0
x=7.55 or x=-2.05(corr. to 3 sig. fig.)
參考: me
收錄日期: 2021-04-28 14:38:06
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20070904000051KK03186