Question

计算下面各题 1 2 + 1 3 =	4 7 + 2 5 =
6 7 - 1 2 =	3 5 + 5 6 =
8 9 - 3 4 =	5 7 - 5 14 =
1- 2 5 =	4 5 - 1 3 =
1 6 + 3 8 =	8 9 - 5 6 =

Answer 1

分析：异分母分数的加减法则：先通分，再根据同分母分数的加减法则计算．依此即可求解．

解答：解：

1 2 + 1 3 = 5 6	4 7 + 2 5 = 34 35
6 7 - 1 2 = 5 14	3 5 + 5 6 = 43 30
8 9 - 3 4 = 5 36	5 7 - 5 14 = 5 14
1- 2 5 = 3 5	4 5 - 1 3 = 7 12
1 6 + 3 8 = 13 24	8 9 - 5 6 = 1 18

点评：考查了分数的加法和减法，关键是熟练掌握计算法则，正确进行计算．