Question

Let A = [(2,-1,1),(-1,2,-1),(1,-1,2)] and 4B = [(3,1,-1),(1,3,x),(-1,1,3)]. If B is the inverse of A, then the vlue of x is ...

(a) 2

(b) 4

(c) 3

(d) 1

Answer 1

(d) 1

Given B is the inverse of A