If the matrices `A` & `B`, given by $ A = \begin{bmatrix} x+y & y-z \\ 5-t & 7+x \end{bmatrix} $, $ B = \begin{bmatrix} t-x & z-t \\ z-y & x+z+t \end{bmatrix} $, are equal, then find the values of `x, y, z, t`