Solve the System of Equations Algebraically for Real Values of X

Multiple Choice

Solve the system of equations algebraically for real values of x and y. $$\left\{ \begin{array} { l } x ^ { 2 } + y ^ { 2 } = 20 \\x + y = 6\end{array} \right.$$

A) $\quad ( 2,4 ) , ( 4,2 )$
B) $\quad ( 4,4 ) , ( 4,4 )$
C) $\quad ( 2,4 ) , ( 2,4 )$
D) $( 4,2 ) , ( 4,2 )$
E) no solution