题目内容
计算下列各题
(1)-3-[-5+(1-2x
)÷(-2)]
(2)-32÷
×(-
)2-(-32×
)×(-1)4
(3)-49
×48.
(1)-3-[-5+(1-2x
| 2 |
| 3 |
(2)-32÷
| 8 |
| 3 |
| 2 |
| 3 |
| 1 |
| 2 |
(3)-49
| 23 |
| 24 |
分析:(1)根据有理数运算法首先将除法转化为乘法,进而去小括号,分级运算得出即可;
(2)根据有理数运算法则,先算乘方再算乘除进而得出即可;
(3)利用乘法分配律得出即可.
(2)根据有理数运算法则,先算乘方再算乘除进而得出即可;
(3)利用乘法分配律得出即可.
解答:解:(1)-3-[-5+(1-2x
)÷(-2)]
=-3-[-5+(1-
)×(-
)]
=-3-(-5+
)
=
;
(2)-32÷
×(-
)2-(-32×
)×(-1)4
=-9×
×
-(-9×
)×1
=-
+
=3;
(3)-49
×48
=(-49-
)×48
=-49×48-
×48
=-2398.
| 2 |
| 3 |
=-3-[-5+(1-
| 4 |
| 3 |
| 1 |
| 2 |
=-3-(-5+
| 1 |
| 6 |
=
| 11 |
| 6 |
(2)-32÷
| 8 |
| 3 |
| 2 |
| 3 |
| 1 |
| 2 |
=-9×
| 3 |
| 8 |
| 4 |
| 9 |
| 1 |
| 2 |
=-
| 3 |
| 2 |
| 9 |
| 2 |
=3;
(3)-49
| 23 |
| 24 |
=(-49-
| 23 |
| 24 |
=-49×48-
| 23 |
| 24 |
=-2398.
点评:此题主要考查了有理数的混合运算,正确掌握运算法则是解题关键.
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