A = [{1 2} {0 1}] and X = I + adj (A) + (adj A)^2 + … adj (A)^10 then sum of elements of X is

Question

\(A=\begin{bmatrix} 1 & 2 \\ 0 & 1 \\ \end{bmatrix}\) and X = I + adj (A) + (adj A)² + … adj (A)¹⁰ then sum of elements of X is

(1) 88 

(2) -88 

(3) 124 

(4) 0

Answer 1

Correct option is (2) -88 

⇒ Sum of elements = -110 + 22 = -88