Question

三、怎么算简便就怎样算。 1/4+3/7+4/7+3/4 2. 8/9-1/4+1/2 3. 3/8+5/6+5/8 4. 2-1/8-7/8 5. 1+3/4-7/12

三、怎么算简便就怎样算。
1/4+3/7+4/7+3/4 2. 8/9-1/4+1/2 3. 3/8+5/6+5/8 4. 2-1/8-7/8 5. 1+3/4-7/12
6. 5/8+1/4-3/4
急急急！

Answer 1

1/4+3/7+4/7+3/4
=1/4+3/4+3/7+4/7
=(1/4+3/4)+(3/7+4/7)
=1+1==2

2. 8/9-1/4+1/2
=8/9+(1/2-1/4)
=8/9+1/4
=32/36+9/36
=41/36

3. 3/8+5/6+5/8
=(3/8+5/8)+5/6
=1+5/6
=11/6

4. 2-1/8-7/8
=2-(1/8+7/8)
=2-1
=1

5. 1+3/4-7/12
=1+9/12-7/12
=1+1/6
=7/6
6. 5/8+1/4-3/4
=5/8-1/2
=5/8-4/8
=1/8