6 songs
The way to find this answer is to divide 18 by 3, which is six, which means that after every six songs a commercial is played.
Hope this was helpful and that I explained it correctly.
Answer:
what do you need help on?
Answer:

Step-by-step explanation:
Comparing it with quadratic equation
, we get:
a = 1 . b = 4 and c = 5
So,
Discriminant = 
D = (4)²-4(1)(5)
D = 16 - 20
D = -4
Hence,
Discriminant = -4
![\rule[225]{225}{2}](https://tex.z-dn.net/?f=%5Crule%5B225%5D%7B225%7D%7B2%7D)
Hope this helped!
<h3 /><h3>~AH1807</h3>