Find the values of a and b such that \(R = \begin{pmatrix} 3& b \\ 4 & a \end{pmatrix} \begin{pmatrix} 7a \\ 2 \end{pmatrix} = \begin{pmatrix} 43 \\ 30 \end{pmatrix}\).
\( a=-1, b=10\)
\( a=2, b=11\)
\( a=1, b=11\)
\( a=5, b=-1\)