脱式计算. 25×4/5+2.5% 9.6-11÷7+1/7×4 12×[(11/6-2/3)×3]

问题描述:

脱式计算.
25×
4
5
+2.5%
9.6-11÷7+
1
7
×4
12×[(
11
6
-
2
3
)×3]

(1)25×

4
5
+2.5%
=20+2.5%
=20.025;
(2)9.6-11÷7+
1
7
×4
=9.6-
11
7
+
4
7

=9.6-(
11
7
-
4
7

=9.6-1
=8.6;
(3)12×[(
11
6
-
2
3
)×3]
=12×[
11
6
×3-
2
3
×3]
=12×[
11
2
-2]
=12×
11
2
-12×2
=66-24
=42.