Solve each system of equations using substitution method. \begin{array}{l} 5 x+2 y=16 \\ x+8 y=26 \end{array} \begin{array}{l} c+6 d=7 \\ -c-2 d=-2 \end{array} \begin{array}{l} 8 p+7 q=43 \\ 2 p-7=-q

\end{array} \begin{array}{l} -5 a+b=8 \\ 7 a+9 b=-32 \end{array} \begin{array}{l} -5=2 m+6 n \\ 4 m+5 n-18=0 \end{array} \begin{array}{l} v=2-6 \mathrm{u} \\ 9 u+2 v=3 \end{array} \begin{array}{l} r+2 s=4 \\ 3 s+r=1 \end{array} \begin{array}{l} 6 y+5 z=0 \\ 3 z=7 y+53 \end{array}