Question

Find the matrix X for which:
`[(5, 4),(1,1)]` X=`[(1,-2),(1,3)]`

Answer 1

`[(5, 4),(1,1)]` X =`[(1,-2),(1,3)]`

Let A = `[(5,4),(1,1)], "B" = [(1,-2),(1,3)]` . Now, |A| = 5 - 4 = 1

adj A = `[(1,-1),(-4,5)]^"t"=[(1,-4),(-1,5)]`

X = A^-1B

= `("adj A")/|"A"|`. B = `[(1,-4),(-1,5)][(1,-2),(1,3)]`

X = `[(-3,-14),(4,17)]`