用简便方法计算,要写出简算过程. 714﹣2.83﹣3.17; 45×; 1400﹣398.
(3.2+3.2+3.2+3.2) ×2.5
+-
3600÷45×90
(2.5-2.5×0.6)÷0.4
0.5÷[一(一)]