Answer:
Both of these sentences are correct <em>grammatically</em>. Yes, really.
However, each sentence has a <em>different meaning</em>.
I tried <u>to solve</u> the problem, but I couldn't.
I tried <u>solving</u> the problem, but I couldn't.
Explanation:
“The author only presents one side of the issue, and this means it is not a valid argument”
It is not a valid argument because he didn’t include a rebuttal. In every argument you mention why the other side could be right, but then backpedal explaining why it isn’t.
Answer: The word furiously shows that he wants the bell to ring a 9:35 as soon as possible
Explanation: