For this case we have the following equation:

We must solve the equation by following the steps below:
We subtract 1 from both sides of the equation:

On the right side of the equation we have that different signs are subtracted and the sign of the major is placed:

We add x to both sides of the equation:

We divide between 4 on both sides of the equation:

Thus, the correct option is option B
Answer:

Option B
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.
To write this equation, you need use the formula y=mx+b.
m represents the slope and b represents the y intercept.
The y intercept is the point where the line touches the y axis. In this case, the y-intercept is 1.
The slope is just rise over run from one coordinate to another. The slope is 2/-1 which could be simplified as -2. The slope just means that we are going up 2 and left 1 to get to a new coordinate.
The equation is y=-2x+1
Have a good day! :)
X is something you could factor out or 4x
From the information given:
Random wins 2000 800 400 0
Probabilities 1/10^4 4/10^4 10/10^4 9985/10^4
thus the expectation will be:
E(x)=[2000+4*800+4000+9985*0]/10^4
E(x)=9200/10000
E(x)=$0.92