I don't believe he has come up with a good solution to this problem so far,___?

has he

don't 中的 not 是否定从句中 has 的 即hasn't come up with ,所以

用has he

而如果从句中没有has 的话，即not 否定的是 comes 的话 ，这时候才用

does he

Do I ?

i don't believe .. , do I ?
我不相信 。。，我有相信吗 ？

I don't believe he has come up with a good solution to this problem so far,(has he)?

does him
乞今为止,我不相信这个问题他能够提出这么好的解决方法,他能吗？(does him)

does him

has he