We can't see what you're trying to say.
86 opposite of it so it would be87
To find the inverse, interchange the variables and solve for y.
f^-1 (x) = 4 + x/2
Answer:
One answer would be -2.155.
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.