First, we would need to create an equation for this problem. Let x represent the number of songs he can download.
$0.25x = $3
Or
$3 = $0.25x
Now, all you would need to do is isolate the x (get it alone). To do this, you would need to divide both sides of the equal sign by $0.25.
$3 = $0.25x
12 = x
x = 12
Liam could download 12 songs with $3 dollars.
I hope this helps!