Considere as matrizes reais:

$$A=\left(\begin{array}{lrc}{x}^2& & 1\\ 2& & y+z\end{array}\right)$$

$$B=\left(\begin{array}{lrc}9& & z\\ y& & -x\end{array}\right)$$

Se $A=B^t$, então $y+z$ é igual a