问题
解答题
用简便方法计算
|
答案
(1)2011×
,17 2010
=(2010+1)×
,17 2010
=2010×
+1×17 2010
,17 2010
=17+
,17 2010
=17
;17 2010
(2)
+15 16
-15 13
+7 16
,11 13
=(
-15 16
)+(7 16
+15 13
),11 13
=
+2,1 2
=2
;1 2
(3)(
+7 8
)÷23 24
,1 48
=(
+7 8
)×48,23 24
=
×48+7 8
×48,23 24
=42+46,
=88;
(4)25%×
×4×7 15
,5 7
=(25%×4)×(
×7 15
),5 7
=1×
,1 3
=
.1 3