Solve the System of Equations Using Substitution $$\left\{ \begin{array} { l } x ^ { 2 } + y ^ { 2 } = 61 \\x - y = 1\end{array} \right.$$

Multiple Choice

Solve the system of equations using substitution.
- $$\left\{ \begin{array} { l } x ^ { 2 } + y ^ { 2 } = 61 \\x - y = 1\end{array} \right.$$

A) x = 4, y = 5; x = 5, y = 4
B) x = 4, y = -5; x = 5, y = -4
C) x = -4, y = -5; x = 5, y = 4
D) x = -4, y = 5; x = -5, y = 4