$[Easy](E-$analysis$)$

Find the $GSof$

$x^{\text{'}}=Ax$

$bye-$analysis method, where

$(1)$

$A=\left[\begin{array}{cc}1& 1\\ 4& 1\end{array}\right]$

$(2)$

$(3)$

$A=\left[\begin{array}{cc}1& 1\\ 0& 1\end{array}\right]$

$A=\left[\begin{array}{cc}1& 1\\ -1& 1\end{array}\right]$