you know that a linear equation has a straight line as it's graph.
If you have the 2 linear equations
then you know that there are infinite many common points if
There is no solution (or there aren't any common points) if
With your problem:
1. Rearrange your equations ( , )
2. Use the general equations which I mentioned above
3. For confirmation only: Infinite many solutions with m = -5 and no solution with m = 3.