如果a-b=5,那么3a+7+5b-6(a+1/3b)=_.

问题描述:

如果a-b=5,那么3a+7+5b-6(a+

1
3
b)=______.

3a+7+5b-6(a+

1
3
b),
=3a+7+5b-6a-2b,
=-3a+3b+7,
=-3(a-b)+7,
=-3×5+7,
=-8.
故答案是:-8.