Question

wee

求解，謝謝

5.解方程式2|x+1 |+|x-2|-x=8
【解答】x=-2 或4
6.設x為實數
2

Answer 1

✨ ベストアンサー ✨

Ny-Ålesund

分段討論

(1) x > 2
2(x + 1) + (x - 2) - x - 8 = 0
2x + 2 + x - 2 - x - 8 = 0
2x = 8
x = 4 並確認有在一開始設定的範圍內

2. -1 < x < 2
2(x + 1) + (2 - x) - x - 8 = 0
2x + 2 - x + 2 - x - 8 = 0
無解

3. x < -1
2(-x - 1) + (2 - x) - x - 8 = 0
-2x - 2 - x + 2 - x - 8 = 0
4x = -8
x = -2 並確認有在一開始設定的範圍內