x-2的绝对值减去x+1的绝对值加上2乘以x-4的绝对值
=2-x-(x+1)+2(4-x)
=1-2x+8-2x
=9结果不对吧？=2-x-(x+1)+2(4-x)=2-x-x-1+8-2x=9-4x