计算:(1)(+25)-(-35);(2)(-25)-(-35);(3)12-13;(4)(-12)-13;(5)(-1)-(-12);(6)(-1)-112;(7)213-(-314);(8)445

题目简介

计算:(1)(+25)-(-35);(2)(-25)-(-35);(3)12-13;(4)(-12)-13;(5)(-1)-(-12);(6)(-1)-112;(7)213-(-314);(8)445

题目详情

计算:
(1)(+
2
5
)-(-
3
5
);
(2)(-
2
5
)-(-
3
5
);
(3)
1
2
-
1
3

(4)(-
1
2
)-
1
3

(5)(-1)-(-
1
2
);
(6)(-1)-1
1
2

(7)2
1
3
-(-3
1
4
);
(8)4
4
5
-7
5
6
题型:解答题难度:中档来源:不详

答案


(1)
∵(+class="stub"2
5
)-(-class="stub"3
5
)=class="stub"2
5
+class="stub"3
5
=1,
∴(+class="stub"2
5
)-(-class="stub"3
5
)=1,
(2)
∵(-class="stub"2
5
)-(-class="stub"3
5
)=(-class="stub"2
5
)+class="stub"3
5
=class="stub"1
5

∴(-class="stub"2
5
)-(-class="stub"3
5
)=class="stub"1
5

(3)
class="stub"1
2
-class="stub"1
3
=class="stub"1
2
+(-class="stub"1
3
)=class="stub"1
6

class="stub"1
2
-class="stub"1
3
=class="stub"1
6

(4)
∵(-class="stub"1
2
)-class="stub"1
3
=(-class="stub"1
2
)+(-class="stub"1
3
)=-class="stub"5
6

∴(-class="stub"1
2
)-class="stub"1
3
)=-class="stub"5
6

(5)
∵(-1)-(-class="stub"1
2
)=(-1)+class="stub"1
2
=-class="stub"1
2

∴(-1)-(-class="stub"1
2
)=-class="stub"1
2

(6)
∵(-1)-1class="stub"1
2
=(-1)+(-1class="stub"1
2
)=-2class="stub"1
2

∴(-1)-1class="stub"1
2
=-2class="stub"1
2

(7)
∵2class="stub"1
3
-(-3class="stub"1
4
)=2class="stub"1
3
+3class="stub"1
4
=5class="stub"7
12

∴2class="stub"1
3
-(-3class="stub"1
4
)=5class="stub"7
12

(8)
∵4class="stub"4
5
-7class="stub"5
6
=4class="stub"4
5
+(-7class="stub"5
6
)=-3class="stub"1
30

∴4class="stub"4
5
-7class="stub"5
6
=-3class="stub"1
30

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