Find the volume V of the solid obtained by rotating the region bounded by the given curves about the specified line. x

Step-by-step explanation:

According to the given situation, the calculation of volume of the solid is shown below:-

Here we will consider the curves that is

Now, rotating the line for the line x which is equals to 7

So, the inner radio is

7 - 7 = 0

and the outer radius is

Now, the area of cross section is

The volume is

now we will put the values into the above formula

After solving the above equation we will get

well, because the $0.25 is an added cost depending on how many minutes, the answer would be y = 30 + 0.25x.