Solve the System by the Substitution Method $$\left\{ \begin{array} { r r } 9 x + y = & 0 \\- 9 x + y = & - 18\end{array} \right.$$

question 74

Multiple Choice

Solve the system by the substitution method.
- $$\left\{ \begin{array} { r r } 9 x + y = & 0 \\- 9 x + y = & - 18\end{array} \right.$$

• A) \(\varnothing\)
• B) \(\{ ( 1 , - 9 ) \}\)
• C) \(\{ ( x , y ) \mid 9 x + y = 0 \}\)
• D) \(\{ ( - 1,9 ) \}\)

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