能简算的用简便方法计算. (54+9/13)÷9 13÷(1/4+5/6)×3/4 (5/6-3/4)÷3/10 3.1×99+3.1 5/7×16.31-2.31÷7/5 36÷[(5/6-1/3)×3].
问题描述:
能简算的用简便方法计算.
(54+
)÷9 9 13
13÷(
+1 4
)×5 6
3 4
(
-5 6
)÷3 4
3 10
3.1×99+3.1
×16.31-2.31÷5 7
7 5
36÷[(
-5 6
)×3]. 1 3
答
(1)(54+
)÷9,9 13
=(54+
)×9 13
,1 9
=54×
+1 9
×9 13
,1 9
=6+
,1 13
=6
;1 13
(2)13÷(
+1 4
)×5 6
,3 4
=13×
×12 13
,3 4
=9;
(3)(
-5 6
)÷3 4
,3 10
=
÷1 12
,3 10
=
;5 18
(4)3.1×99+3.1,
=3.1×(99+1),
=3.1×100,
=310;
(5)
×16.31-2.31÷5 7
7 5
=
×16.31-2.31×5 7
,5 7
=
×(16.31-2.31),5 7
=
×14,5 7
=10;
(6)36÷[(
-5 6
)×3],1 3
=36÷[
×3],1 2
=36÷
,3 2
=24.