"Did you solve for N?"
"Yes. I didn't think that helped though."
"Well show me what you got anyway."
...
"By the way, in the future you should make sure to show any and all work you have done regardless of whether you think it's right or even relevant. It usually speeds things along."
I assumed the constant was equal to zero.
If you want to be rude because I've made honest mistakes, I don't think your help will be productive for either of us.