| 计算 (1)1÷(
(2)(-12-4)÷(-2); (3)-2.7×56+7.9×(-56)+6×5.6(用简便方法计算). |
答案:
(1)1÷(
=1÷(-
=1×(-7)×21 =-147;(2)(-12-4)÷(-2) =-16÷(-2) =8;(3)-2.7×56+7.9×(-56)+6×5.6 =-2.7×56-7.9×56+0.6×56 =(-2.7-7.9+0.6)×56 =-10×56 =-560. |

| 计算 (1)1÷(
(2)(-12-4)÷(-2); (3)-2.7×56+7.9×(-56)+6×5.6(用简便方法计算). |
答案:
(1)1÷(
=1÷(-
=1×(-7)×21 =-147;(2)(-12-4)÷(-2) =-16÷(-2) =8;(3)-2.7×56+7.9×(-56)+6×5.6 =-2.7×56-7.9×56+0.6×56 =(-2.7-7.9+0.6)×56 =-10×56 =-560. |