Question

Let $A=\left\lgroup\begin{array}{ccc}1&-1&1\\2&1&-3\\1&1&1\end{array}\right\rgroup\ and\ B=\left\lgroup\begin{array}{ccc}4&2&2\\-5&0&\alpha\\1&-2&3\end{array}\right\rgroup$. If B is the inverse of matrix A, then a is
(a) 5
(b) –1
(c) 2
(d) –2

Answer 1

tex]. If B is the inverse of matrix A, then a is

(a) 5

(b) –1

(c) 2

(d) –2