计算下面各题,怎样计算简便就怎样计算. 7 8 + 4 7 + 1 8 1

计算下面各题,怎样计算简便就怎样计算. 7 8 + 4 7 + 1 8 1 2 + 1 4 + 1 8 1- 5 7 - 2 7 .
2024-12-03 22:20:36
推荐回答(1个)
回答(1):

(1)
7
8
+
4
7
+
1
8

=
7
8
+
1
8
+
4
7

=1+
4
7

=1
4
7


(2)
1
2
+
1
4
+
1
8

=
3
4
+
1
8

=
7
8


(3)1-
5
7
-
2
7

=1-(
5
7
+
2
7
),
=1-1,
=0.