下面各题,怎样算简便就怎样算:31÷(52﹣32)×53 1512×(65+43)+54 97×115+92×115 [21﹣(43﹣53)]÷107.
(1)2.1×2.6+7.4×5.4+2.6×3.3 (2)0.147×368+0.632×l47.
用简便方法计算,并要写出主要的简算过程.①﹣+②×12.5×8×0.4 ③×12.
简算:7.25﹣3+3.75﹣6 49×(+)×25×+÷﹣.
用简便方法计算.72×53+41×24 981+5×9810+49×981.
用简便方法计算(54+ )÷9 9.25×9.9+92.5% 0.4×1.25×25×8.