解:(1)
-(
),
=
-(
×
-
),
=
(
-
),
=
-
,
=
,
=
,
=3
;
(2)
,
=
×
+
×
,
=
×(
),
=
×1,
=
;
(3)(
)÷
,
=
×18+
×18+
18,
=6+3+2,
=11;
(4)
-(
+
),
=
-
,
=1-
,
=
;
(5)3
×9.7+37.5×0.13-15÷4,
=3.75×9.7+3.75×1.3-3.75,
=3.75×(9.7+1.3-1),
=3.75×10,
=37.5.
分析:(1)運(yùn)用加減、乘除法的計(jì)算法則進(jìn)行計(jì)算,先算括號(hào)內(nèi)部的在計(jì)算括號(hào)外面的.
(2)先把除號(hào)為乘號(hào),再運(yùn)用乘法的分配律進(jìn)行計(jì)算.
(3)把括號(hào)外的除以這個(gè)數(shù)變?yōu)槌艘赃@個(gè)數(shù),然后再運(yùn)用乘法的分配律進(jìn)行計(jì)算.
(4)這道題運(yùn)用c-(a+b)=c-a-b進(jìn)行計(jì)算,使計(jì)算更加簡便.
(5)把分?jǐn)?shù)轉(zhuǎn)化成小數(shù),把37.5轉(zhuǎn)化成3.75×10,然后再運(yùn)用乘法的分配律進(jìn)行計(jì)算.
點(diǎn)評(píng):按照分?jǐn)?shù)乘除法的計(jì)算法則進(jìn)行計(jì)算,靈活的運(yùn)用乘法的分配律進(jìn)行計(jì)算.