The problem given in the image involves three matrices $A$, $B$, and $C$, and you are asked to solve for $x + y + z$, where $x$, $y$, and $z$ are variables in the matrices. Here's the information from the image:

Matrices are given as:

[ A = \begin{bmatrix} -2 & x \ 6 & 3 \end{bmatrix}, \quad B = \begin{bmatrix} -5 & 14 \ y & -2 \end{bmatrix}, \quad