First, solve the given system of linear equations.
Second, multiply the first equation by 4 (which was an arbitrary choice).  Add your result to the 2nd equation.
You should now have the following:
First equation:  No change:             2x + 7y = 1
Second equation:  4(-3x – 4y = 5) = -12x -16y = 20
Solve this new system of linear equations.  Do you (or do you not) obtain the same solution as your earlier one?