Use the Gauss-Jordan Method to Solve the System of Equations $\begin{array} { c } 7 x - 5 y = - 21 \\- 4 x + 3 y = 12\end{array}$

Multiple Choice

Use the Gauss-Jordan method to solve the system of equations. If the system has infinitely many solutions, give the
solution with y arbitrary.
$\begin{array} { c } 7 x - 5 y = - 21 \\- 4 x + 3 y = 12\end{array}$

A) $\{ ( - 3,1 ) \}$
B) $\varnothing$
C) $\{ ( - 3,0 ) \}$
D) $\{ ( - 4,1 ) \}$