Question

1-4/7等于多少？2/5-1/9等于多少？5/6-1/3等于多少？1/9+1/6等于多少？

Answer 1

1-4/7=7/7-4/7=3/7。
2/5-1/9=18/45-5/45=13/45。
5/6-1/3=5/6-2/6=3/6=1/2。
1/9+1/6=2/18+3/18=5/18。

Answer 2

这些都是分数运算，只需要统一分母即可：
解：1-4/7
=（7-4）/7
=3/7
2/5-1/9
=（18-5）/45
=13/45

5/6-1/3
=（5-2）/6
=3/6
=1/2

1/9+1/6
=（2+3）/18
=5/18

Answer 3

分数加减要通分母，分母相同，分子相加减
即
1-4/7
=7/7-4/7
=3/7
2/5-1/9
=18/45-5/45
=13/45
5/6-1/3
=5/6-2/6
=3/6
=1/2
1/9+1/6
=2/18+3/18
=5/18

Answer 4

①1-4/7
=7/7-4/7
=3/7;
②2/5-1/9
=18/45-5/45
=13/45
③5/6-1/3
=15/18-6/18
=9/18
=1/2
=0.5
④1/9+1/6
=2/18+3/18
=5/18

Answer 5

1-4/7=7/7-4/7=3/7
2/5-1/9=18/45-5/45=13/45
5/6-1/3=5/6-2/6=3/6=1/2
1/9+1/6=2/18+3/18=5/18
先通分，求分母的最小公倍数，然后分子再相加减。