\(If $a,b,c$ are positive integers less than $13$ such that\begin{align*} 2ab+bc+ca&\equiv 0\pmod{13}\\ ab+2bc+ca&\equiv 6abc\pmod{13}\\ ab+bc\)

yes, I have tried lots of stuff, adding them together but that doesn't work, I used wolfram and it doesn't even give me an answer

halpppp

Guest Oct 15, 2020