format rat;

A = [1, 0; 1, -2]; % Problem 1

A = [-1, 1; -4, -1]; % Problem 2

A = [0, 1; -1, 0]; % Problem 3

A = [1, 0; 1, 1]; % Problem 4

A = [0, 1; 1, 0]; % Problem 19

A= [1, 0; 0, -2]; % Problem 20

A =[0, 1; -1, 0]; % Problem 26

% Compute the eigensystem for the matrix A:
%
m = size(A, 1);
e = eig(A)
for ii=1:m
    rref(A - e(ii)*eye(m))
end