Solve the Following System of Quadratic Equations Algebraically by the Method

Multiple Choice

Solve the following system of quadratic equations algebraically by the method of substitution.
$$\left\{ \begin{array} { l } 8 x ^ { 2 } - 6 y ^ { 2 } + 80 = 0 \\8 x + 4 y = 0\end{array} \right.$$

A) $( \sqrt { 5 } , - 2 \sqrt { 5 } ) , ( \sqrt { 7 } , - 2 \sqrt { 7 } )$
B) $( - \sqrt { 7 } , 2 \sqrt { 7 } ) , ( \sqrt { 7 } , - 2 \sqrt { 7 } )$
C) $( - \sqrt { 7 } , - 2 \sqrt { 7 } ) , ( \sqrt { 7 } , - 2 \sqrt { 7 } )$
D) $( - \sqrt { 5 } , - 2 \sqrt { 5 } ) , ( \sqrt { 5 } , 2 \sqrt { 5 } )$
E) $( - \sqrt { 5 } , 2 \sqrt { 5 } ) , ( \sqrt { 5 } , - 2 \sqrt { 5 } )$