问题
解答题
用简便方法计算. 23-
(
0.4×1.25×25×8. |
答案
(1)23-
-12 17
,5 17
=23-(
+12 17
),5 17
=23-1,
=22;
(2)(
+3 4
)×20,2 5
=
×20+3 4
×20,2 5
=15+8,
=23;
(3)0.4×1.25×25×8,
=(0.4×25)×(1.25×8),
=10×10,
=100.
用简便方法计算. 23-
(
0.4×1.25×25×8. |
(1)23-
-12 17
,5 17
=23-(
+12 17
),5 17
=23-1,
=22;
(2)(
+3 4
)×20,2 5
=
×20+3 4
×20,2 5
=15+8,
=23;
(3)0.4×1.25×25×8,
=(0.4×25)×(1.25×8),
=10×10,
=100.