Put x=12,12,37,65 and then go for $mod x$ Then we can get the value of $yt$ in terms of $mod x$ For $x=12$, $yt=2(mod 12)$ 14,37 and 65 are the remaining values so trying, we get $yt=14*37$ Do subcases where y =14 or 37 and also we get that $z=65$ Rest we can solve to get $x=12, y=37, z=65, t=14$