如图,l∥m,矩形ABCD的顶点B在直线m上,则∠α= 度.
若ax>b,ac2<0,则x________.
满足-2x>-12的非负整数有________________________.
若x+y>x-y,y-x>y,那么 (1)x+y>0,(2)y-x<0,(3)xy≤0,(4)<0中, 正确结论的序号为________.
x<y得到ax>ay的条件应是____________.
若,,则x______.