Find which 2 people have no solutions.
See Beto's equation... \(3m=3m+5\)
⇒\(3m-3m=5\)
But \(0≠5\)
Now Mark's equation... \(6-n=-n+2\)
⇒\(-n+n=2-6\)
But \(0≠-4\)
∴Beto's and Mark's equations have no solutions.