Step by step
The question
Question: work out this sum of two matrices.
[1, 2] + [3; 4]
A matrix is numbers in rows and columns, inside big brackets.
Each number in a matrix is called an entry.
1 Check the sizes
They are not the same size.
Some entries have no partner in the same place.
So we cannot add them: there is no answer.
1 × 2 and 2 × 1: not the same size
Answer
1 × 2 and 2 × 1: not the same size