计算下面各题（能用简便方法的用简便方法）．
22.7×1.25×O.8 3.91×2.8+6.09×2.8
9.83×（3.8﹣2.3）+1.5×6.17 3.6×51+36×4.9
7.8×9.9 5.4﹣3.2+12.6﹣7.8
7.2×4.1﹣9.5÷7.6 8.125×3+7×8.125
（0.75×27.5﹣3.405）÷0.8 [0.16+（3﹣1.272）÷1.2]×1.25．
