# Lecture - Linear Algebra MT22, I

> Source: https://ollybritton.com/notes/uni/prelims/mt22/linear-algebra/lectures/1/ · Updated: 2022-10-18 · Tags: uni, lecture

### Flashcards
How many elementary row operations are there?::
3

What is the first elementary row operation?::
Swapping two rows.

What is the second elementary row operation?::
Multiplying by a non-zero scalar.

What is the third elementary row operation?::
Adding one row to another.

What’s Gauss elimination?::
The process of systematically using EROs to introduce zeroes into the lower triangle.

What’s Gauss-Jordan elimination?::
Like Gauss elimination except you also make the upper triangle zeroes.

When is it necessary to use the first ERO (swapping the rows)?::
When it’s not possible to make a zero using the other rows.

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