25%,0.25都等于1/4，把它们转化成1/4后，提取公因式1/4,(1/4)*(6/7)=3/7
=3/7x1/4+1/4x2/7+1/4x1/7 =1/4x（3/7+2/7+1/7） =1/4x6/7 =3/14
｛7/1+7/2+7/3｝*4/1
