问题
解答题
用简便方法计算,要求写出简算的主要过程. (
5.58-
|
答案
(1)(
-3 4
)×12÷0.1,2 3
=(
×12-3 4
×12)÷0.1,2 3
=(9-8)÷0.1,
=1÷0.1,
=10;
(2)
×[3 8
÷(8 9
+5 6
)],3 4
=
×[3 8
÷8 9
],19 12
=
×3 8
×8 9
,12 19
=
;4 19
(3)5.58-
+5.42-3 8
,5 8
=(5.58+5.42)-(
+3 8
),5 8
=10-1,
=9;
(4)
×40-7 16
÷5 16
,1 40
=
×40-7 16
×40,5 16
=(
-7 16
)×40,5 16
=
×40,1 8
=5.