Solve the System $\left\{ \begin{array} { r } x ^ { 2 } + y ^ { 2 } = 49 \\x - y = 3\end{array} \right.$

Multiple Choice

Solve the system $\left\{ \begin{array} { r } x ^ { 2 } + y ^ { 2 } = 49 \\x - y = 3\end{array} \right.$ by substitution. Which of the following equations is the outcome, when substituting the equation $x - y = 3$ into $x ^ { 2 } + y ^ { 2 } = 49$ ?

A) $2 y ^ { 2 } + 9 = 49$
B) $2 y ^ { 2 } + 6 y + 9 = 49$
C) $2 y ^ { 2 } + y + 9 = 49$
D) $2 y ^ { 4 } + 9 = 49$