脱式计算(能简便算的要简算,写出主要步骤)①3.6-2.8+7.4-7.2         ②817÷23+123×917+12

2025-03-22 12:51:34
推荐回答(1个)
回答1:

①3.6-2.8+7.4-7.2 
=3.6+7.4-(2.8+7.2)
=11-10
=1;

8
17
÷23+
1
23
×
9
17
+
1
23

=
8
17
×
1
23
+
1
23
×
9
17
+
1
23
×1
=(
8
17
+
9
17
+1)×
1
23

=2×
1
23

=
2
23


③(
1
2
+
1
3
)÷
3
5
-
17
18

=
5
6
÷
3
5
-
17
18

=
25
18
-
17
18

=
4
9


④18÷[
5
6
+(
5
8
-
1
3
)]
=18÷(
5
6
+
7
24

=18÷
27
24

=16.