Solve the System by the Addition Method $$\left\{ \begin{array} { l } 5 x + 7 y = 54 \\5 x + 2 y = 69\end{array} \right.$$

Multiple Choice

Solve the system by the addition method.
- $$\left\{ \begin{array} { l } 5 x + 7 y = 54 \\5 x + 2 y = 69\end{array} \right.$$

A) $\varnothing$
B) $\{ ( - 15,5 ) \}$
C) $\{ ( 15 , - 3 ) \}$
D) $\{ ( x , y ) \mid 5 x + 2 y = 69 \}$