Can I help my best friend pseudo-cheat?
That sounds like a bad idea but so why would you help him cheat?
My best friend is always helping me out.
It is good to help others but not to do things that are wrong like cheating. It is not good and if caught you will also be in trouble.
I had no way to say no.
There is always a way to say no. Cheating in school will not make you smarter, and you should let your friend know that it's not right. It's better to just study together and ace the test on your own ability, because it will be a lot more satisfying and productive.