Answer:
Option C.
Step-by-step explanation:
Note: x is missing in the second equation.
The given equations are
[tex]4x-7y=-12[/tex]
[tex]-2x+6y=11[/tex]
It can we written as
[tex]\left[\left.\begin{matrix}4 & -7\\ -2 & 6\end{matrix}\right|\begin{matrix}-12\\ 11\end{matrix}\right][/tex]
Divide row 1 be 4.
[tex]\left[\left.\begin{matrix}1 & -\dfrac{7}{4}\\ -2 & 6\end{matrix}\right|\begin{matrix}-3\\ 11\end{matrix}\right][/tex]
Applying [tex]R_2\to R_2+2R_1[/tex], we get
[tex]\left[\left.\begin{matrix}1 & -\dfrac{7}{4}\\ 0 & \dfrac{5}{2}\end{matrix}\right|\begin{matrix}-3\\ 5\end{matrix}\right][/tex]
Applying [tex]R_2\to \dfrac{2}{5}R_2[/tex], we get
[tex]\left[\left.\begin{matrix}1 & -\dfrac{7}{4}\\ 0 & 1\end{matrix}\right|\begin{matrix}-3\\ 2\end{matrix}\right][/tex]
Applying [tex]R_1\to R_1+\dfrac{7}{4}R_2[/tex], we get
[tex]\left[\left.\begin{matrix}1 & 0\\ 0 & 1\end{matrix}\right|\begin{matrix}\dfrac{1}{2}\\ 2\end{matrix}\right][/tex]
Since [tex]x=\dfrac{1}{2}\text{ and }y=2[/tex], therefore required ordered pair is [tex](\dfrac{1}{2},2)[/tex].
Hence, option C is correct.
