1、已知不等式3（5x+2）+5

1、已知不等式3（5x+2）+5<4x-6（x+1）,化简|2X-1|-|1-2X| =
3(5x+2)+5＜4x-6(x+1)
15x+6+5＜4x-6x-6
15x+2x＜-6-11
17x＜-17
x＜-1
∴|2X-1|-|1-2X| =-(2x-1)-(1-2x)=-2x+1-1+2x=0

2.
x+(k-1)/2=2-x/3
6x+3k-3=12-2x
6x+2x=15+3-3k
8x=18-3k
x=(18-3k)/8＞2
18-3k＞16
-3k＞-2
k＜2/3

3.(x²+1)/(2-x)＜0的解集是
∵x²+1＞0
.(x²+1)/(2-x)＜0
∴2-x＜0
∴x＞2