# Linear Algebra-MIT-Gilbert Strang-(L7-L8)

# Lecture 7 Ax= 0, Nullspace

- Elimination of A. Rank = Number of Pivot in the Matrix.

2. Pivot column, and **Free column**. Free columns don’t create a new dimension. Free columns can be represented by pivot columns. So in x2 and x4 can be assigned with any number.