Help/Support Apt-get update worked but gave errors at the end.

[Acehoundzz 5 iPhone 6s 9.3.2]

Hello after finally getting the apt-get update to work, it gave me four errors at the end. it says:

GPG  error: repo.biteyourapple.net ./ Release: The following signautres couldn't be verified because the public key is not available: NO_PUBKEY (random numbers and letters)

and the other three errors are the same it is just different repos (Cokepokes.github.io; repo.insanelyi.com; and yuan.duowan.com) 

 

I tried deleting the repos but I get the same errors before that say that I need to update apt-get. what do I do? 

 

Thanks in advance

[Acehoundzz 5 iPhone 6s 9.3.2]

bump

 

[Acehoundzz 5 iPhone 6s 9.3.2]

please someone