I'm a beginner taking Linear Algebra and i seem to have trouble understanding the following notations Matrix Notations
I understand that in the second picture 1x3 denotes a Matrix with 1 row and 3 columns, but what are the numbers at the bottom of F?
It means the entries of matrix come from the field $ \mathbb{F}_2 $. I guess you have not learnt something like 'field' so don't worry about it, you can just take it as the remainder of integer $ 2 $, and there are two element in $ \mathbb{F}_2 $ one is $ 0 $ another is $ 1 $ which represents even number and odd number respectively.