Question

直接写得数． 1 2 + 5 6 =	1- 3 4 =	1 3 + 3 5 =
1 5 + 1 3 =	1 4 + 1 8 =	1 7 + 2 5 =
1 4 - 1 5 =

Answer 1

考点：分数的加法和减法

专题：运算顺序及法则

分析：异分母分数相加减，先根据分数的基本性质把异分母分数通分成同分母分数，再根据同分母分数加减法的法则进行计算得解．

解答：

解： 1 2 + 5 6 = 4 3	1- 3 4 = 1 4	1 3 + 3 5 = 14 15
1 5 + 1 3 = 8 15	1 4 + 1 8 = 3 8	1 7 + 2 5 = 19 35
1 4 - 1 5 = 1 20

点评：此题考查异分母分数加减法，关键是先通分成同分母分数，要注意结果要化成最简分数．