能用简便方法计算的则用简便方法简算:6/7-(1/6-1/12) 9/19-(8/9-10/19) 8/15+1/3-8/15

问题描述:

能用简便方法计算的则用简便方法简算:
6/7-(1/6-1/12) 9/19-(8/9-10/19) 8/15+1/3-8/15

1.6/7-(1/6-1/12)=6/7-1/12=(72-7)/84=65/84.
2.9/19-(8/9-10/19)=9/19+10/19-8/9=1-8/9=1/9.
3.8/15+1/3-8/15 =8/15-8/15+1/3=1/3.