2 questions of Absolute value

2009-05-02 7:32 am
Q1. 〡 2x+7〡-〡 x-3〡= 16

Q2. 〡x-2〡( x -3 ) = 2



Ans1. -26 or 6

Ans2. 4
更新1:

Q2 when x<2 step2:: (2-x)(x-3)=2 點解要乘負號既???

回答 (1)

2009-05-02 7:48 am
✔ 最佳答案
1 when x<-7/2
〡 2x+7〡-〡 x-3〡= 16
-7-2x-3+x= 16
-x=26
x=-26
when -7/2<x<3
〡 2x+7〡-〡 x-3〡= 16
2x+7-3+x= 16
3x=12
x=4 (rejected)
when x>3
〡 2x+7〡-〡 x-3〡= 16
2x+7-x-3= 16
x=6
So x=-26 or 6

2when x<2
〡x-2〡( x -3 ) = 2
(2-x)(x-3)=2
x^2-5x+8=0
no solution
when x>2
〡x-2〡( x -3 ) = 2
(x-2)(x-3)=2
x^2-5x+4=0
x=4 or 1 (rejected)







收錄日期: 2021-04-26 14:00:29
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20090501000051KK02222

檢視 Wayback Machine 備份