Determine whether each system of linear equations has'unique solution,'no solution' or 'infinitely many solutions'. \begin{array}{l} y+7 x=50 \\ 14 x-5 y=-28 \end{array} \begin{array}{l} 3 s=-18 r+15 \\ 12 r+2 s=10

\end{array} \begin{array}{l} 54=-6 a+18 b \\ 3 a-9 b=-27 \end{array} \begin{array}{l} 2 q=20+5 r \\ 6 q-15 r=12 \end{array} \begin{array}{l} -4 s+2 t-13=0 \\ 8 s-6 t=42 \end{array} \begin{array}{l} 5 y-20 z=45 \\ y-4 z=9 \end{array} \begin{array}{l} 14 m=3 n+8 \\ -6 n+28 m=12 \end{array} \begin{array}{l} -11=-20 u+5 v \\ 6 u+v=22 \end{array} \begin{array}{l} -4 p+12 q-36=0 \\ -p+3 q-9=0 \end{array} \begin{array}{l} -c+10 d=0 \\ -20 d+2 c=3 \end{array}