Question

If A = `[(1, 2),(2, 3)] "and B" = [(2, 1),(3, 2)], "C" = [(1, 3),(3, 1)]` find the matrix C(B – A).

Answer 1

A = `[(1, 2),(2, 3)]`

B = `[(2, 1),(3, 2)]`

C = `[(1, 3),(3, 1)]`

B – A = `[(2, 1),(3, 2)] - [(1, 2),(2, 3)]`

= `[(2 - 1, 1 - 2),(3 - 2, 2 - 3)]`

= `[(1, -1),(1, -1)]` 

C(B – A) = `[(1, 3),(3, 1)] xx [(1, -1),(1, -1)]`

= `[(3 xx 1 + 3 xx 1, 1 xx (-1) + 3 xx (-1)),(3 xx 1 + 1 xx 1, 3 xx (-1) + 1 xx (-1))]`

= `[(1 + 3, -1 - 3),(3 + 1, -3 - 1)]`

= `[(4, -4),(4, - 4)]`