Let A = [a_ij]_2×3

So, the elements in a 3×4 matrix are

a₁₁, a₁₂, a₁₃, a_14, a₂₁, a₂₂, a₂₃,a₂₄,a_31,a_32,a_33,a₃₄

A = ……(1)

a₁₁ = 1 a₁₂ = 2 a₁₃ = 3 a₁₄ = 4

a₂₁ = 1 a₂₂ = 2 a₂₃ = 3 a_{24 =} 4

a₃₁ = 1 a₃₂ = 2 a₃₃ = 3 a₃₄ = 4

So, from (1)

A =