Hello!
If a problem has infinite solutions you will end with a 0, with one it will end with any number and for no solutions you will get a equations that does not equal each other
Ex: 5 = 9
You can do the bottom first since it looks the easiest.
5x - 3 = 5x - 2
subtract 5x from both sides
0x -3 = -2
Add 3 to both sides
0x = 1
0x

So it has no solutions
Next you can do the top one
6y + 2 = 3y + 4
subtract 3y from both sides
3y + 2 = 4
Subtract 2 from both sides
3y = 2
Divide both sides by 3
y =

Since this came to a regular number it has one solution
The only one left has the be the one with infinite solutions by we can check
4x + 4y + 8 = x + y + 2
since the left side is the same as the right just multiplied by 4 it has infinite solutions
So the first one has one solution
The second one has infinite solutions
And the third one has no solutions
Hope this helps!