Answer: say something along the lines of “hey i’m really struggling with this homework from (insert teacher) and i wanted to ask if you could help me?”
Explanation: this leaves opportunity for them to say no. it leaves a choice for them to make and i feel like they might understand if you word it this way. make sure to talk them outside of asking for homework as well, or else they’ll stop replying to those homework questions (i did that to ppl bc i got irritated that they kept asking me). just be as nice as you can and if they say no, say it’s okay and be understanding.