-2x-1≥4a+1-2x≥4a+1+1-2x≥2(2a+1)-x≥2a+1x≤-2a-1
4a+2x+2<=0也就是2a+x+1<=0
-2X-4a≥1-1-2X-4a≥0X-2a≥0X≥2a
大哥你这一共一个等式两个未知数怎么化