Đâu là sự khác biệt giữa I feel like I can do it. và I think I can do it. ?Hãy thoải mái đưa ra các câu ví dụ nhé.

Both of them mean "できると思う", usually in English you say "I think..." when you "feel" too therefore they're interchangeable. In my experience, it's more common for people to use "I think..." than to use "I feel", though when a person wants to put emphases on the fact that he acts based on "feeling" a certain way, he's doing so by saying "I feel..."

I also feel (no pun intended lol) that saying "I feel" sounds a lot more stronger or certain that what you're saying is "true" or may be successful, and "I think" in certain context may come up as hesitant or unsure for example:
I think that I can do it, but I feel like I can't... ("rationally I feel I can do something but my "feelings" are contradicting my rationality rofl).