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计算:(1)-7+3-5+20(2)223+(-223)+(513)-(-512)(3)4.25+(-2.18)-(-2.75)+5.18(4)43-(-87)-2-(13)−17.

题目详情
计算:
(1)-7+3-5+20
(2)2
2
3
+(-2
2
3
)+(5
1
3
)-(-5
1
2

(3)4.25+(-2.18)-(-2.75)+5.18
(4)
4
3
-(-
8
7
)-2-(
1
3
1
7
▼优质解答
答案和解析
(1)-7+3-5+20
=-7-5+3+20
=-12+23
=11;

(2)2
2
3
+(-2
2
3
)+(5
1
3
)-(-5
1
2

=2
2
3
-2
2
3
+5
1
3
+5
1
2

=10
5
6


(3)4.25+(-2.18)-(-2.75)+5.18
=4.25-2.18+2.75+5.18
=4.25+2.75+5.18-2.18
=7+3
=10;

(4)
4
3
-(-
8
7
)-2-(
1
3
1
7

=
4
3
+
8
7
-2-
1
3
1
7

=
4
3
-
1
3
+
8
7
1
7
-2
=1+1-2
=0.