你好解 X2-3|X|-4>=0当X>0时(X-4)(X+1)>=0x>=4或X<=-1(舍去)当X<0时(X+4)(X-1)>=0X<=-4或x>=1(舍去)X>=9/XX(9-X2)<=0X属于(-oo,-3]并(0,3]所以[1,3]bing(-oo,-3]bing[4,+oo) 谢谢