1. 4/5 - 3/4 =
(4/5) - (3/4) = 0.175
2. 5/6 + 2/3 =
(5/6) + (2/3) = 1.5
3. 3/4 - 1/2 =
(3/4) - (1/2) = 0.5
4. 2/3 + 3/4 =
(2/3) + (3/4) = 0.625
5. 5/6 - 3/4 =
(5/6) - (3/4) = 0.16666666666666669
6. 1/2 - 1/3 =
(1/2) - (1/3) = 0.16666666666666674
7. 2/5 + 3/8 =
(2/5) + (3/8) = 0.875
8. 4/9 - 1/3 =
(4/9) - (1/3) = 0.11111111111111116
9. 3/5 - 2/7 =
(3/5) - (2/7) = 0.08571428571428572
10. 5/8 + 2/9 =
(5/8) + (2/9) = 0.7083333333333334
11. 7/9 - 5/8 =
(7/9) - (5/8) = 0.10555555555555557
12. 4/5 + 2/7 =
(4/5) + (2/7) = 0.9142857142857143
12道分式计算及答案如下：（1）12分之12等于1，（2）12分之24等于2，（3）2分之4等于2，（4）2分之6等于3，（5）2分之8等于4，（6）2分之10等于5，（7）2分之一等于0.5，（8）4分之一等于0.25，（9）5分之一等于0.2，（10）10分之一等于0.1，（11）3分之9等于3，（12）3分之12拿于4。
