do sb a favor 帮某人的忙

Would you please do me a favor to...?

您能够帮我一个……忙好吗?

Would you please do me a favor, sir?

您能够帮我一个忙吗，先生?

Would you please do me a favor to open the window?

您能够帮我打开窗户吗?

A:I can't solve this math problem, would you please do me a favor ?

我解不开这道数学题，您能够帮我一下吗?

B:Sorry, I'm not good at math, you can go to John for help.

对不起，我不擅长数学，你可以找约翰帮忙。