Solve the System by the Addition Method $$\begin{array} { l } 2 x ^ { 2 } + 2 y ^ { 2 } = 18 \\2 y - x = 12\end{array}$$

Multiple Choice

Solve the system by the addition method. $$\begin{array} { l } 2 x ^ { 2 } + 2 y ^ { 2 } = 18 \\2 y - x = 12\end{array}$$

A) $\{ ( 9,6 ) , ( - 9 , - 6 ) \}$
B) $\{ ( 0,0 ) \}$
C) $\{ ( 18,6 ) , ( - 18,6 ) \}$
D) { }