Identify Systems That Do Not Have Exactly One Ordered-Pair Solution $$\begin{array} { l } y = 18 - 5 x \\5 x + y = 28\end{array}$$

Multiple Choice

Identify Systems That Do Not Have Exactly One Ordered-Pair Solution
- $$\begin{array} { l } y = 18 - 5 x \\5 x + y = 28\end{array}$$

A) $\{ ( 12,13 ) \}$
B) $\{ ( 15,3 ) \}$
C) $\{ ( x , y ) \mid 5 x + y = 18 \}$
D) $\varnothing$ )