Solve the system $\left\{ \begin{array} { l }
9 x - y = 7 \
8 x + 9 y = - 9
\end{array} \right.$ by Cramer s rule. Write the determinant $D _ { x }$ .
A) $\mid \begin{array} { c c }
9 & - 1 \
8 & 9
\end{array}$
B) $\left| \begin{array} { c c }
7 & - 1 \
- 9 & 9
\end{array} \right|$
C) $\begin{array} { c c }
9 & 7 \
8 & - 9
\end{array}$
D) $\left| \begin{array} { c c }
- 7 & - 1 \
9 & 9
\end{array} \right|$

Question

Solve the system $\left\{ \begin{array} { l } 
9 x - y = 7 \
8 x + 9 y = - 9
\end{array} \right.$ by Cramer s rule. Write the determinant $D _ { x }$ .
A) $\mid \begin{array} { c c } 
9 & - 1 \
8 & 9
\end{array}$
B) $\left| \begin{array} { c c } 
7 & - 1 \
- 9 & 9
\end{array} \right|$
C) $\begin{array} { c c } 
9 & 7 \
8 & - 9
\end{array}$
D) $\left| \begin{array} { c c } 
- 7 & - 1 \
9 & 9
\end{array} \right|$

Quizplus · Accepted Answer

The determinant $D_x$ is formed by replacing the first column of the coefficient matrix with the constants from the right-hand side of the equations.

Solve the System {9x−y=78x+9y=−9\left\{ \begin{array} { l } 9 x - y = 7 \\8 x + 9 y = - 9\end{array} \right.{9x−y=78x+9y=−9​

Solve the System $\left\{ \begin{array} { l } 9 x - y = 7 \\8 x + 9 y = - 9\end{array} \right.$