Are there choices? If there are, you should list them because there are some equivalents.
![\left[\begin{array}{cc}4&16\\12&3\end{array}\right] \\ \left[\begin{array}{cc}-68&16\\21&3\end{array}\right] = x \\ \left[\begin{array}{cc}4&-68\\12&21\end{array}\right] = y \\](https://img.qammunity.org/2019/formulas/mathematics/high-school/1268ow4n49jkx0zbz0gofzhgirwwzkafmi.png)
I'm assuming that you can solve these things. The top determinant comes to -180. The x value comes to - 540. When divided by the top one x = 3
The bottom determinant (y) comes to 900 and when divided by - 180 makes y = - 5. The checks out with actually solving the system of equations some other way.