题目内容
计算
(1)(-
)×3÷3×(-
);
(2)(-
)×
×(-
)×(-
);
(3)(-
)+(-
)-(-2);
(4)4.6-(-
+1.6-4)-
;
(5)-(-18)+12-15+(-17);
(6)-7.5+4.7-(-8.9)+(-6);
(7)-14+(-
)×(-2)3;
(8)(-72)×(
-
+
-
);
(9)-4÷(-1
)-[
×(-
)-(-0.5)];
(10)36×(-
)-19×(-
)-27×(-
).
(1)(-
| 1 |
| 3 |
| 1 |
| 3 |
(2)(-
| 1 |
| 2 |
| 2 |
| 3 |
| 3 |
| 4 |
| 4 |
| 5 |
(3)(-
| 2 |
| 9 |
| 7 |
| 9 |
(4)4.6-(-
| 3 |
| 4 |
| 3 |
| 4 |
(5)-(-18)+12-15+(-17);
(6)-7.5+4.7-(-8.9)+(-6);
(7)-14+(-
| 1 |
| 8 |
(8)(-72)×(
| 3 |
| 4 |
| 7 |
| 6 |
| 11 |
| 12 |
| 13 |
| 24 |
(9)-4÷(-1
| 3 |
| 5 |
| 5 |
| 6 |
| 3 |
| 4 |
(10)36×(-
| 3 |
| 5 |
| 3 |
| 5 |
| 3 |
| 5 |
考点:有理数的混合运算
专题:
分析:(1)(2)先判定符号,再按照运算顺序计算;
(3)(4)(5)(6)先化简,再分类计算;
(7)先算乘方,再算乘法,最后算加法;
(8)(10)利用乘法分配律简算;
(9)先算乘法和除法,再算括号里面的,最后算括号外面的.
(3)(4)(5)(6)先化简,再分类计算;
(7)先算乘方,再算乘法,最后算加法;
(8)(10)利用乘法分配律简算;
(9)先算乘法和除法,再算括号里面的,最后算括号外面的.
解答:解:(1)原式=1×
×
=
;
(2)原式=
×
×
×
=
;
(3)原式=-
-
+2
=-1+2
=1;
(4)原式=4.6+
-1.6+4-
=3+4
=7;
(5)原式=18+12-15-17
=30-32
=-2;
(6)原式=-7.5+4.7+8.9-6
=-13.5+13.6
=0.1;
(7)原式=-1+(-
)×(-8)
=-1+1
=0;
(8)原式=(-72)×
-(-72)×
+(-72)×
-(-72)×
=-54+84-66+39
=-120+123
=3;
(9)原式=-4×(-
)-[-
+0.5]
=
-(-
)
=
+
=
;
(10)原式=-
×(36-19-27)
=-
×(-10)
=6.
| 1 |
| 3 |
| 1 |
| 3 |
=
| 1 |
| 9 |
(2)原式=
| 1 |
| 2 |
| 2 |
| 3 |
| 3 |
| 4 |
| 4 |
| 5 |
=
| 1 |
| 5 |
(3)原式=-
| 2 |
| 9 |
| 7 |
| 9 |
=-1+2
=1;
(4)原式=4.6+
| 3 |
| 4 |
| 3 |
| 4 |
=3+4
=7;
(5)原式=18+12-15-17
=30-32
=-2;
(6)原式=-7.5+4.7+8.9-6
=-13.5+13.6
=0.1;
(7)原式=-1+(-
| 1 |
| 8 |
=-1+1
=0;
(8)原式=(-72)×
| 3 |
| 4 |
| 7 |
| 6 |
| 11 |
| 12 |
| 13 |
| 24 |
=-54+84-66+39
=-120+123
=3;
(9)原式=-4×(-
| 5 |
| 8 |
| 5 |
| 8 |
=
| 5 |
| 2 |
| 1 |
| 8 |
=
| 5 |
| 2 |
| 1 |
| 8 |
=
| 21 |
| 8 |
(10)原式=-
| 3 |
| 5 |
=-
| 3 |
| 5 |
=6.
点评:此题考查有理数的混合运算,注意运算的顺序和符号的判定,正确利用运算定律简算.
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