For matrix $A=\begin{bmatrix} 3 & 1\\7 & 5\end{bmatrix},$ the values of x and y so that $A^2+xI=yA$ are :

$x=6, y = 8 $ $x=8, y = 6 $ $x=8, y = 8 $ $x=6, y = 6 $

$x=8, y = 8 $