The rows and columns
Considering representation. Really interesting how it is something that is discussed. The notation considered is the column vector, but the representation with parentheses still denotes the column vector. Distinction.
The study of the linear combinations. Three-dimensional vectors. The linear combination for a vector is just the multiplication with a scalar. Then, it can consider other linear combinations adding other vector multiplied by a scalar. This is key and we are learning.
Really great learning.