Help with solving linear equations using Gaussian elimination...

I have been following notes online to finish my assignment and this is what confuses me:

**Gaussian Elimination.** Consider a linear system.

**1.** Construct the augmented matrix for the system;

2. Use elementary row operations to transform the augmented matrix into a triangular one;

3. Write down the new linear system for which the triangular matrix is the associated augmented matrix;

4. Solve the new system. You may need to assign some parametric values to some unknowns, and then apply the method of back substitution to solve the new system. For number 2, it says to use elementary row operations to transform an augmented matrix into a triangular one...

Do each of the leading coefficients have to be a 1?

The notes that my teacher wrote on the board show that she changed each coefficient to a 1 by using the rules.

I am confused (Speechless)