Formal:
* 请回答我 (qǐng huídá wǒ): This is the most direct and formal way to say it. It literally means "please answer me."
* 请您回答我 (qǐng nín huídá wǒ): This is even more formal, using the honorific "您 (nín)" for the person you are addressing.
Informal:
* 请你回答我 (qǐng nǐ huídá wǒ): This is a less formal way to say it, using the pronoun "你 (nǐ)" instead of "您 (nín)."
* 你回答我一下 (nǐ huídá wǒ yīxià): This is even more casual, literally meaning "answer me for a bit."
* 回答我一下好吗 (huídá wǒ yīxià hǎo ma): This is a polite request, adding "好吗 (hǎo ma)" at the end, which means "okay?"
The best option will depend on your relationship with the person you are talking to and the situation.