Solve the System by the Substitution Method $x ^ { 2 } + y ^ { 2 } = 25$

Multiple Choice

Solve the system by the substitution method.
- $x ^ { 2 } + y ^ { 2 } = 25$ $x - y = 1$

A) $\{ ( 4,3 ) , ( - 3 , - 4 ) \}$
B) $\{ ( - 4,3 ) , ( - 3,4 ) \}$
C) $\{ ( 4 , - 3 ) , ( 3 , - 4 ) \}$
D) $\{ ( - 4 , - 3 ) , ( - 3 , - 4 ) \}$