Determine whether the eigenvalues of each matrix are distinct real, repeated real, or complex.

$\left[\begin{array}{cc} 2 &-1\cr 0 &1 \end{array}\right]$ ? Distinct Real Repeated Real Complex

$\left[\begin{array}{cc} -5 &6\cr 0 &1 \end{array}\right]$ ? Distinct Real Repeated Real Complex

$\left[\begin{array}{cc} -5 &-1\cr 1 &-7 \end{array}\right]$ ? Distinct Real Repeated Real Complex

$\left[\begin{array}{cc} 1 &3\cr -6 &3 \end{array}\right]$ ? Distinct Real Repeated Real Complex