Should I use my money for down payment or the home line credit?

[Liping Kong]

hello!

I have a really confusing question and hope somebody will help me. we put an offer on one house, we need pay 20% which is 34000 for the down payment, we have $34000 cash but we also can use home line credit, the rate is variable 3.5%, I am not sure should I use my owe cash or the home line credit? if I can put the $34000 somewhere and get the over 3.5% return, that will be worth to using the home line credit, but so far, the money just sitting there.

I know this question maybe a little silly, but anybody can give me some suggestion, I will be appreciated.

Thank you!