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加减混合运算(1)[(-3)-(+9)]-(-2)(2)(−23)−(+12)−(−56)−(+13)−(+112)(3)434-(+3.85)-(-334)+(-3.15)(4)|3-4|+(-5-8)-|-1+5|-(5-20)

题目详情
加减混合运算
(1)[(-3)-(+9)]-(-2)
(2)(−
2
3
)−(+
1
2
)−(−
5
6
)−(+
1
3
)−(+1
1
2
)
(3)4
3
4
-(+3.85)-(-3
3
4
)+(-3.15)
(4)|3-4|+(-5-8)-|-1+5|-(5-20)
▼优质解答
答案和解析
(1)[(-3)-(+9)]-(-2)
=(-3-9)+2
=-12+2
=-10;

(2)(-
2
3
)-(+
1
2
)-(-
5
6
)-(+
1
3
)-(+1
1
2

=-
2
3
-
1
3
+
5
6
-
1
2
-1
1
2

=-1+
5
6
-2
=-2
1
6


(3)4
3
4
-(+3.85)-(-3
3
4
)+(-3.15)
=4
3
4
+3
3
4
-3.85-3.15
=8.5-7
=1.5;

(4)|3-4|+(-5-8)-|-1+5|-(5-20)
=1-13-4+15
=16-17
=-1.