You know that the system of equations has no solution because you get something funky when trying to solve for x like:
[tex]7 = 25[/tex]
This happens because the system dont intersect.
Now there are infinite number of solutions when its the same equation (it may look different because it was multiplied by a scalar).
But in general, you will get something like
[tex]7 = 7[/tex]
If you have any questions feel free to ask!