题目内容
计算下面各题.
1-
×
×(5-
)
(0.75-
)×(
+
)
[1-(
+
)]÷
.
1-
5 |
7 |
21 |
25 |
1 |
6 |
2 |
3 |
(0.75-
3 |
16 |
2 |
9 |
1 |
3 |
[1-(
1 |
4 |
3 |
8 |
3 |
4 |
分析:本题根据四则混合运算的运算顺序计算即可:先算乘除,再算加减,有括号的要先算括号里面的.
解答:解:(1)1-
×
=1-
,
=
;
(2)
×(5-
)
=
×
,
=
;
(3)(0.75-
)×(
+
),
=(
-
)×(
+
),
=
×
,
=
;
(4)[1-(
+
)]÷
,
=[1-
]÷
,
=
×
,
=
.
5 |
7 |
21 |
25 |
=1-
3 |
5 |
=
2 |
5 |
(2)
1 |
6 |
2 |
3 |
=
1 |
6 |
13 |
3 |
=
13 |
18 |
(3)(0.75-
3 |
16 |
2 |
9 |
1 |
3 |
=(
3 |
4 |
3 |
16 |
2 |
9 |
1 |
3 |
=
9 |
16 |
5 |
9 |
=
5 |
16 |
(4)[1-(
1 |
4 |
3 |
8 |
3 |
4 |
=[1-
5 |
8 |
3 |
4 |
=
3 |
8 |
4 |
3 |
=
1 |
2 |
点评:当算式中同时含有中括号与小括号时,要先算小括号里面的,再算中括号里面的.
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