Let A & Mn (R) with A²+3A = -21. Show that if: I eigenvalue of A => A=-1 VJ=-2₁ Let A = [X+² 2X₂ ] 2x 3 X-L with eigenvalues A₁, A₂. Find XE C да, да. such that a) 2₁ + 1₂ = 3 b) 1 1 + ng 2₁ c) 1₁²2² +2₂2²2² = 1 1 (Hint: a² +62 = (a + b)²_206) (12) Let A & Mun (IR) be a matrix and let B = P-LAP hoh-Si with PEMnn (IR) a matrix. Show that A,B have the same eigenvalues. 1-singular