I'm confused with those exercises. Do i need to use RREF to do them?

1.-

64 -30 Find eigenvalues and eigenvectors for the matrix 140 -66 The smaller eigenvalue has an eigenvector The larger eigenvalue has an eigenvectorFind the eigenvalues >1 2 and associated unit eigenvectors uj, uz of the symmetric matrix 18 147 A = 14 -3 The smaller eigenvalue A1 = has associated unit eigenvector u1 = The larger eigenvalue 12 = has associated unit eigenvector u2 = Note: The eigenvectors above form an orthonormal eigenbasis for A