x小于等于0
2x^2+1-x≤2
2x^2-x-1≤0
(x-1)(2x+1)≤0
-1/2≤x≤1
综上-1/2≤x≤0

x大于0
-2x-x≤2
3x≥-2
x≥-3/2
综上x>0

综上x≥-1/2