9-4= 10-3= 9-3=10-7= 7-5= 6-4=
++++++++
2.009×43+20.09×2.9+200.9×0.28
(2.5×)÷(×1.8)-0.75÷
20142014×20142013-20142015×20142012
1375+450÷18×25