Question

i tried (solve)................................the problem but i couldn't

Answer 1

Answer:

Both of these sentences are correct grammatically. Yes, really.

However, each sentence has a different meaning.  

I tried to solve the problem, but I couldn't.

I tried solving the problem, but I couldn't.

Explanation:

Answer 2

Answer:

I think (to solve)

Itried to solve the problem but i couldn't