Solve the System of Equations by Using Substitution $$\left\{ \begin{array} { r } x + 7 y = - 2 \\3 x + y = 34\end{array} \right.$$

Multiple Choice

Solve the system of equations by using substitution.
- $$\left\{ \begin{array} { r } x + 7 y = - 2 \\3 x + y = 34\end{array} \right.$$

A) $x = - 2 , y = 3$
B) $x = 7 , y = 12$
C) $x = 12 , y = - 2$
D) $x = 3 , y = 7$