Week 2 Assignment: Why multiply in the AddRows function?

Here’s the function in the week 2 assignment. I’m a bit confused as to why it’s necessary to multiply the rows when adding? Especially as there is already a ‘MultiplyRow’ function.

Here in the slides when explaining how to add matrix rows together there is no multiplication involved. Why include that functionality in the assignment function. Seems a but superfluous.

def AddRows(M, row_num_1, row_num_2, row_num_1_multiple):
    M_new = M.copy()     
    # multiply row_num_1 by row_num_1_multiple and add it to the row_num_2, 
    # exchanging row_num_2 of the matrix M_new with the result
    None = None
    return M_new

This is a handy operation for the topic of solving a system of simultaneous equations.