Question

If A = `[(2, 3),(1, 2)]`, B = `[(1, 3, 2),(4, 3, 1)]`, C = `[(1),(2)]`, D = `[(4, 6, 8),(5, 7, 9)]`, then which of the sums A + B, B + C, C + D and B + D is defined?

Answer 1

Only B + D is defined since matrices of the same order can only be added.