直接写得数.
+ = | - = | 3+ = | 1- = | -(1- )= |
- = | - = | + = | + = | 1- - = |
解:
+ =1, | - = , | 3+ =3 , | 1- = , | -(1- )= , |
- = , | - = , | + = , | + = , | 1- - = . |
分析:同分母分数相加减,分母不变,分子相加减;异分母分数相加减,先通分,化成同分母的分数再计算;其中
-(1-
)先算小括号里面的减法,再算括号外的减法;1-
-
根据连续减去两个数等于减去这两个数的和简算.点评:本题考查了简单的分数加减法的计算,根据运算法则快速准确的求出运算结果.
+
=
-
=
=
=
-
-
=
=
+
=
,
,
,
,
,
,
,
.