❖ To solve a linear system of equations by Gaussian elimination, we have to put it in Row Echelon Form (REF). Then, we have to solve it by using backward substitution.

❖ This Linear Algebra video tutorial provides a basic introduction to Gaussian elimination which is a process that involves elementary row operations with \(3 \times 3\) matrices which allows you to solve a system of linear equations with \(3\) variables \((x, y, z)\).

So, you need to convert the system of linear equations into an augmented matrix \([ A | b ]\) and use matrix row operations to convert the \(3 \times 3\) matrix into the Row Echelon Form (REF). Then, solve it by using back substitution.