解:(1)
-
+
,
=
+
,
=
;
(2)
+(
+
),
=
+(
+
),
=
+
,
=
;
(3)7-(
-
),
=7-
,
=6
;
(4)1
-
-
,
=1
-(
+
),
=1
-1,
=
;
(5)
+
+
+
,
=(
+
)+(
+
),
=1+1,
=2;.
(6)
+
-
,
=
-
,
=
;
(7)5-
-
,
=5-(
+
),
=5-1,
=4;
(8)
+
+
,
=
+(
+
),
=
+1,
=1
;
(9)
-(
-
),
=
-
,
=
.
分析:(1)先通分,再進(jìn)行計(jì)算;
(2)先算括號(hào)里的加法,再算括號(hào)外的加法;
(3)先算括號(hào)里的減法,再算括號(hào)外的減法;
(4)運(yùn)用減法的運(yùn)算定律進(jìn)行簡算;
(5)運(yùn)用加法的交換律、結(jié)合律進(jìn)行簡算;
(6)先通分,再進(jìn)行計(jì)算;
(7)運(yùn)用減法的運(yùn)算定律進(jìn)行簡算;
(8)運(yùn)用加法的結(jié)合律進(jìn)行簡算;
(9)先算括號(hào)里的減法,再算括號(hào)外的減法.
點(diǎn)評(píng):考查了分?jǐn)?shù)四則混合運(yùn)算的順序,靈活運(yùn)用運(yùn)算定律進(jìn)行簡算.